EP3072545A1 - Apparatus and method for detecting disconnection of an intravascular access device - Google Patents

Apparatus and method for detecting disconnection of an intravascular access device Download PDF

Info

Publication number
EP3072545A1
EP3072545A1 EP16168110.1A EP16168110A EP3072545A1 EP 3072545 A1 EP3072545 A1 EP 3072545A1 EP 16168110 A EP16168110 A EP 16168110A EP 3072545 A1 EP3072545 A1 EP 3072545A1
Authority
EP
European Patent Office
Prior art keywords
system
connector
blood
end
electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP16168110.1A
Other languages
German (de)
French (fr)
Inventor
Michael J. Wilt
Jason M. Sachs
Kevin L. Grant
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deka Products LP
Original Assignee
Deka Products LP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US25673509P priority Critical
Application filed by Deka Products LP filed Critical Deka Products LP
Priority to EP10795810.0A priority patent/EP2493526B1/en
Publication of EP3072545A1 publication Critical patent/EP3072545A1/en
Application status is Pending legal-status Critical

Links

Images

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/36Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
    • A61M1/3621Extra-corporeal blood circuits
    • A61M1/3653Interfaces between patient blood circulation and extra-corporal blood circuit
    • A61M1/3656Monitoring patency or flow at connection sites; Detecting disconnections
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/36Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
    • A61M1/3621Extra-corporeal blood circuits
    • A61M1/3653Interfaces between patient blood circulation and extra-corporal blood circuit
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/36Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
    • A61M1/3621Extra-corporeal blood circuits
    • A61M1/3653Interfaces between patient blood circulation and extra-corporal blood circuit
    • A61M1/3655Arterio-venous shunts, fistulae
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/36Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
    • A61M1/3621Extra-corporeal blood circuits
    • A61M1/3653Interfaces between patient blood circulation and extra-corporal blood circuit
    • A61M1/3659Cannulae pertaining to extracorporeal circulation
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electro-chemical, or magnetic means
    • G01N27/02Investigating or analysing materials by the use of electric, electro-chemical, or magnetic means by investigating the impedance of the material
    • G01N27/04Investigating or analysing materials by the use of electric, electro-chemical, or magnetic means by investigating the impedance of the material by investigating resistance
    • G01N27/06Investigating or analysing materials by the use of electric, electro-chemical, or magnetic means by investigating the impedance of the material by investigating resistance of a liquid
    • G01N27/07Construction of measuring vessels; Electrodes therefor
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/14Measuring resistance by measuring current or voltage obtained from a reference source
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2205/00General characteristics of the apparatus
    • A61M2205/33Controlling, regulating or measuring
    • A61M2205/3317Electromagnetic, inductive or dielectric measuring means

Abstract

An electrical circuit for measuring the resistance of a liquid between a first and second electrode, the first electrode connected to a first terminal Vta of the electrical circuit, and the second electrode connected to a second terminal Vtb of the electrical circuit, comprising: a capacitor C1 connected on a first end to the first terminal and a capacitor C2 connected on a first end to the second terminal; a known reference resistance Rref connected on a first end to a second end of capacitor C1; switching means for connecting either; a) a first reference voltage V+ to a second end of Rref, and a lower second reference voltage V- to a second end of C2 to form a first switch configuration or; b) the first reference voltage V+ to the second end of C2 and the lower second reference voltage V- to the second end of Rref to form a second switch configuration; and measuring means for measuring a voltage Vsense at the connection between C1 and Rref; wherein the electrical circuit is configured to determine the value of the resistance of the liquid based on the known reference resistance Rref and the observed voltage Vsense for each of the first and second switch configurations.

Description

    CROSS REFERENCE TO RELATED APPLICATIONS
  • The present application is a Non-provisional Application which claims priority from U.S. Provisional Patent Application Serial No. 61/256,735, filed October 30, 2009 and entitled Device and Method for Detecting Disconnection of an Intravascular Access Device, which is incorporated herein by reference in its entirety.
  • BACKGROUND
  • The present invention relates generally to systems and methods to detect disconnection of an indwelling vascular line, such as a catheter or needle, or its attached tubing. If not quickly detected, a disconnection can lead to rapid exsanguination, particularly when the blood in the catheter or tubing is under positive pressure. Examples of circumstances involving positive intravascular pressure include the positive pressure associated with an artery or arterio-venous fistula, or the positive pressure associated with an extracorporeal blood pump circuit. In hemodialysis, for example, a blood pump can generate blood flow rates of 400-500 ml/min, making rapid, reliable disconnect detection particularly desirable. Indeed any medical treatment involving relatively high flow or high pressure extracorporeal circulation (such as, for example, hemoperfusion or cardiopulmonary bypass) can be made safer by having an effective system to monitor the integrity of the arterial (withdrawal) and venous (return) blood lines.
  • In hemodialysis, for example, extracorporeal blood circulation can be accomplished with vascular access using either a single indwelling catheter, or two separate indwelling catheters. In a single catheter system, blood is alternately withdrawn from and returned to the body via the same cannula. A disconnection in this system can be quickly detected by placing an air monitor in the line at or near the pump inlet, because air will be drawn into the line from the disconnection site during the blood withdrawal phase of the pumping. On the other hand, in a two-catheter system, blood is typically continuously withdrawn from the body via one catheter inserted in a blood vessel or fistula, and returned to the body via the second catheter inserted in the same vessel some distance from the first catheter, or in a separate blood vessel altogether. In the two-catheter system, it is also possible to monitor for catheter or tubing dislodgement in the blood withdrawal or `arterial' segment by using a sensor to detect the presence of air being entrained into the arterial tubing as blood is withdrawn from the blood vessel under negative pump pressure and/or positive fistula pressure. However, air-in-line detection cannot reliably detect a disconnection of the venous (return) segment of the extracorporeal circuit. In this case, if the blood-withdrawal path remains intact, air will not be introduced into the line. Thus it is particularly important to be able to detect a disruption in the continuity of the return line from the extracorporeal pump to die vascular access site.
  • Attempts have been made to develop systems to detect dislodgment based on the electrical, mechanical or acoustical properties of blood in the extracorporeal circuit. These systems have not been very effective because of the relatively high impedance of a blood circuit that includes long stretches of tubing, one or more blood pumps, valves, air traps and the like. Furthermore, the electrical interference generated by various devices along the blood path may obscure the signal that one is attempting to monitor.
  • An electrical signal can be introduced into the blood circuit through induction using a field coil surrounding a section of the blood tubing. It may also be introduced through capacitive coupling. For reasons of patient safety, the strength of an electrical signal introduced into the blood circuit necessarily must be small. However, the dielectric properties of the wall of the blood tubing can cause excessive noise or interference when attempting to detect conductivity changes in the blood from an electrical signal introduced through inductive or capacitive coupling. Therefore, it may be more desirable to introduce a brief, small electrical signal through direct contact with the blood path, to limit the length (and therefore impedance) of the blood path being monitored, and to perform the monitoring function at a suitable distance from any interference-producing components.
  • SUMMARY
  • In one aspect, the invention comprises a system for detecting whether a vascular access device, such as a needle, cannula, catheter, etc. becomes disconnected or dislodged from a blood vessel or vascular graft. The system includes a fluid delivery device that provides for the flow of a liquid through a tube or conduit into the blood vessel via an indwelling needle or catheter at a first site on the blood vessel or graft. The fluid may be an electrolyte solution or other solution suitable for intravenous infusion, or it may be blood or blood components. An electrode is disposed to be in contact or fluid communication with the lumen of the conduit, and a second electrode is disposed to be in fluid communication with blood within the blood vessel or graft via a second on the blood vessel or graft. An electronic circuit is connected to the first and second electrodes, and configured to deliver a control signal to the first and second electrodes in order to measure the electrical resistance of the fluid between the first and second electrodes, such that at least one of the electrodes is located closer to the blood vessel or graft than to the fluid delivery device. In some embodiments the electrode is located at about 50-70% of the distance from the fluid delivery device to the blood vessel or graft. In other embodiments. the electrode is located at about 70-90% or more of the distance from the fluid delivery device to the blood vessel or graft. The fluid delivery device can include a pump, either for blood or for other therapeutic or diagnostic fluid. The fluid delivery device can be part of a hemodialysis blood flow circuit. which may or may hot include a blood pump, a dialyzer cartridge, or an air trap and associated tubing. The second electrode may be placed in contact with the lumen of a second conduit or tube that is in fluid communication with the blood vessel or graft at the second site. The second conduit may form part of a fluid flow path from the blood vessel or graft to the fluid delivery device. The fluid in the second conduit may be blood being delivered to an extracorporeal blood flow circuit.
  • The system may comprise a first and second connector connecting a pair of vascular access catheters accessing a blood vessel segment or vascular graft segment at two different sites. The first and second connectors may each connect to a flexible tube leading to the fluid delivery device. Each connector may include an electrode that is exposed to the lumen of the connector. A wire may be attached to each connector, the wire being connectable on its other end to the electronic circuit. The flexible tubes may be double lumen tubes having a first lumen for carrying fluid and a second lumen for carrying a wire. The wires of each tube may be connected on the other end of the tube to a connector for connection to the electronic circuit.
  • The electronic circuit or an associated microprocessor may be configured to convert the voltages measured across terminals connected to the electrodes by the electronic circuit into resistance values. The system may comprise a controller configured to receive a signal from the electronic circuit or microprocessor, the signal representing the electrical resistance between the electrodes, the controller being programmed to trigger an alert signal when the electrical resistance value exceeds a pre-determined threshold. The alert signal may be an audible or visual signal to the person whose blood vessel is being accessed, and optionally an alert signal may include an electrical command to a tubing occluder apparatus. The tubing occluder apparatus may be actuated to mechanically occlude one or more of the tubes leading from the vascular access sites. The tubing occluder may operate in a number of ways, such as, for example electromechanically, hydraulically, or pneumatically.
  • In another aspect, the invention comprises an apparatus for monitoring the continuity between a vascular access device and a blood vessel or vascular graft segment, comprising, a first and second vascular connector, the first connector being attached on a proximal end to a distal end of a fluid-carrying lumen of a first double-lumen tube, and the second connector being attached on a proximal end to a distal end of a fluid-carrying lumen of a second double-lumen tube. The first connector comprises a first electrode in contact with a lumen of the first connector and electrically connected to a wire within a wire-carrying lumen of the first double-lumen tube, and the second connector comprises a second electrode in contact with a lumen of the second connector and electrically connected to a wire within a wire-carrying lumen of the second double-lumen tube. The wire within the first double-lumen tube and the wire within the second double-lumen tube are each connected to an electrical connector at a proximal end of the double-lumen tubes. The distal end of each connector may be configured with a locking feature to provide a reversible, air-tight connection between the connector and a mating connector of a vascular catheter. The proximal end of the double-lumen tubes can be connected to a blood pump on an arterial side, and an air trap on a venous side; and in a hemodialysis system, the blood pump and air trap may each be reversibly connectable to a dialyzer cartridge.
  • In another aspect, the invention comprises a vascular connector comprising a proximal fluid connection end, a distal fluid connection end, and an electrode configured to electrically connect a fluid-carrying lumen of the connector with a wire external to the vascular connector. The proximal end of the connector may be configured to connect with a flexible tube, and the distal end of the connector may be configured to connect with a mating connector of a vascular catheter. The electrode may be installed in a conduit on the connector that connects the lumen of the connector to the exterior of the connector. The electrode may be lodged into the conduit in a manner to provide an air-tight seal between the lumen and the exterior of the connector. An elastomeric member such as an O-ring may be installed between the electrode and the conduit to contribute to the air-tight seal.
  • In another aspect, the invention comprises an electrical circuit for measuring the resistance of a liquid between a first and second electrode, the first electrode connected to a first terminal of the electrical circuit, and the second electrode connected to a second terminal of the electrical circuit, comprising a capacitor C connected on a first end to the first terminal and a capacitor C2 connected on a first end to the second terminal; a known reference resistance Rref connected on a first end to a second end of capacitor C1; switching means for connecting either (a) a first reference voltage V+ to a second end of Rref, and a lower second reference voltage V- to a second end of C2 to form a first switch configuration or; (b) the first reference voltage V+ to the second end of C2 and the lower second reference voltage V- to the second end of Rref to form a second switch configuration; and measuring means for measuring a voltage Vsense at the connection between C1 and Rref; such that the electrical circuit is configured to determine the value of the resistance of the liquid based on the known reference resistance Rref and the observed voltage Vsense for each of the first and second switch configurations. The resistance Rref may be chosen to be a value that permits conductivity measurement of an electrolyte solution or other solution suitable for intravenous infusion. The electrolyte solution may include dialysate solution. The resistance Rref may also be chosen to permit measurement of the resistance of a volume of blood between the first and second electrodes.
  • BRIEF DESCRIPTION OF THE DRAWINGS
    • Figure 1 is a schematic representation of a conductivity circuit in an illustrative embodiment;
    • Figure 2 is a diagram of the electrical waveforms processed by the circuit of Figure 1;
    • Figure 3 is a representative graph of the noise/error sensitivity of the circuit of Figures 1 plotted against the ratio of unknown/reference resistance in the circuit;
    • Figure 4 is a schematic representation of an exemplary blood flow circuit of a hemodialysis system;
    • Figure 5A is a side view of a connector that may be used in the blood flow circuit of Figure 4;
    • Figure 5B is a cross-sectional view of the connector of Figure 5A;
    • Figure 6 is a cross-sectional view of the connector of Figures 5A and 5B, with an attached wire and flexible tubing;
    • Figure 7A is a perspective view of an alternate embodiment of a connector that may be used in the blood flow circuit of Figure 4;
    • Figure 7B is a top view of the connector of Figure 7A;
    • Figure 7C is a cross-sectional view of the connector of Figure 7B;
    • Figures 8A-D are various cross-sectional views of a flexible tube incorporating a conductive wire;
    • Figure 9 is a perspective view of a flexible double-lumen tube having a fluid-carrying lumen and a wire-carrying lumen;
    • Figure 10 is a cross-sectional view of a connector similar to the connector of Figures7A-C, with an attached wire and tubing;
    • Figure 11 is a plan view of an extracorporeal blood flow circuit used in a representative hemodialysis system;
    • Figure 12 is a perspective view of a hemodialysis apparatus configured to receive and operate the extracorporeal blood flow circuit of Figure 11 :
    • Figure 13 is a representative plot of the resistance measured by the conductivity circuit of Figure 1 under various conditions.
    DETAILED DESCRIPTION Conductivity Circuit
  • An exemplary electrical circuit shown in Figure 1 can be used to measure the electrical conductivity or resistance of a subject fluid. In one embodiment, the fluid may be an electrolyte solution or dialysate fluid, and the circuit may ultimately provide a measurement of the conductivity of the fluid to ensure its compatibility for intravascular administration. In addition to monitoring the concentration of dissolved solutes in the fluid, the electrical circuit can also monitor for any interruption in the continuity of the fluid between the electrodes connected to the circuit. For example, it can be used to monitor an intravenous fluid line for the presence of air bubbles, or for the presence of a contaminating substance. In another embodiment, the fluid may be blood, and a change in the measured electrical resistance of a blood flow path (for example, in a conduit) may be used to indicate if a discontinuity occurs between the blood flow path and measuring electrodes. For example, the blood flow path may comprise a column of blood between two electrodes that includes indwelling needles or catheters in a segment of a blood vessel, arterio-venous fistula or graft. Vascular access disconnection can result in the introduction of air into the blood flow path, causing a change in the resistivity of the blood column between the electrodes. The electrical circuit can be readily modified (depending on its application) to adjust for the difference between the impedance of a blood flow path and that of dialysate fluid.
  • The circuit shown in Figure 1 may be used to measure an unknown resistance Rx of a subject media 1 using inexpensive electronic components, particularly where the unknown resistance involves a conductive path through an electrolytic fluid. A switching network 2 comprising a pair of multiplexers allows the connection of nodes VA and VB to reference voltages V+ and V-. The subject media having unknown resistance Rx is connected to terminals VTA and VTB3, and forms a voltage divider with reference resistor Rref 4. To make a conductivity measurement, alternating voltages can be presented to the subject media 1 via switching network 2 to the voltage divider created by the known reference resistor RRef 4 (680 Ω, for example, in the case of dialysate fluid) and the unknown resistance Rx of the subject media 1. The midpoint of the voltage divider 5 is measured. The signal VSense at point 5 is buffered by amplifier 10 to make the input signal Vin of the analog-to-digital converter (ADC) 11. VSense switches between two values as the voltage divider is driven first one way and then the other way. This signal is valid only for a short period of time after switching because the fluid in the conductivity cell 1 is AC coupled into the circuit through capacitors C1 and C2 6. Thus DC-blocking capacitors C1 and C2 6 may be used to prevent DC currents from passing through the unknown resistance (which may include a conductive path through electrolytic fluid or blood). In an embodiment, series capacitors C can each comprise two capacitors in parallel, one having a value, e.g., of 0.1 uF, and the other having a value, e.g., of 10 uF. Series resistors 7 may be used to reduce exposure by the switch network and other sense circuitry to noise and surge voltages. ADC 11 can take multiple samples of the signal as the circuit is switched between the two configurations.
  • The switching network 2 can be driven by a pair of alternating binary control signals 13, 4 that connect VA to V+ and VB to V-during one half-cycle, and VB to V+ and VA to V-during the other half-cycle. This results in a waveform at the Vsense node 5 that is similar to the waveform 20 shown in Figure 2. In this embodiment. VRef is 4 volts, resulting in a Vsense amplitude of less than 4 volts, as shown in Figure 2. A voltage divider 8 creates the voltages V+ and V- that are near the positive reference voltage VRef and near ground, respectively. In one embodiment, R1 can have a value of 10 ohms, and R2 can have a value of 2K ohms When both multiplexers of switching network 2 are commanded to zero, the circuit is at rest and the lower voltage is presented to terminals VTA and VTB 3. When VA is high and VB is low, the higher voltage is presented to the reference resistor RRef 4 and the lower voltage is presented to the subject media 1 having unknown resistance Rx. When VB is high and VA is low, the higher voltage is presented to the subject media 1 having unknown resistance Rx and the lower voltage is presented to the reference resistor RRef 4.
  • A change in voltage ΔVsense before and after each square wave edge, can be shown to depend only on the reference resistance Rref 4, the unknown resistance Rx of subject media 1, and any series resistance (including, e.g., R, 7), and is generally independent of series capacitance C1 or C2 6, since during this short time period the capacitor acts as an incremental short circuit. In particular, Δα = ΔV sense / V + V = R y R ref R th / R y + R ref + R th = ρ 1 / ρ + 1
    Figure imgb0001
    where Ry = Rx +2Rs +Rth, where Rth = source series resistance from multiplexer 2 and voltage divider 8, and p= Ry/(Rref+Rth). (Source series resistance Rth can be derived as the sum of the resistance of multiplexer 2 and the Thevenin equivalent resistance of the voltage divider 8. For example, for R1 = 10ohms, R2 = 2K ohms, then Rth = R1 ∥(R1+R2) = 9.95 ohms). Thus, if Ry is a short circuit, then ρ = 0 and Δα = -1. The sense node's change in voltage ΔVsense is then equal to the voltage change at VB which has an amplitude opposite to the drive node at VA. If Ry is an open circuit, then ρ = ∞ and Δα = 1. The sense node's change in voltage ΔVsense is then equal to the voltage change at the drive node VA. Accordingly, if this change in voltage is measured, the preceding equations can be solved for the unknown resistance Rx: R x = ρ R ref + R th 2 R s R th , where ρ = 1 + Δα / 1 Δα
    Figure imgb0002
  • As shown in Figure 1, a low-pass filter 9 can be formed by resistor Rf and capacitor Cf, to filter out high-frequency noise. In one exemplary arrangement, RF can have a value of 1K Ω, and CF can have a value of 0.001 uF. Buffer amplifier 10 and analog-to-digital converter (ADC) 11 can then measure the sensed voltage for a computer or digital signal processor (not shown).
  • The reference voltages V+ and V- may be advantageously derived from a voltage divider 8 so that V+ is close to the reference voltage VRef of the ADC 11, and V- is close to the ground reference voltage of the ADC 11. For example, for R1 = 10 Ω, R2 = 2 kΩ, and Vref= 4.0V, then V+= 3.980V, and V- = 0.020V. This places both voltages within but near the edges of the active sensing region of the ADC 11, where they can be used for calibration (discussed below). Switch SW1 12 may be used to help calibrate the load resistance sensing.
  • Several improvements may decrease errors related to variations of component values. First, a calibration step can be introduced where VA is switched to V+ for a relatively long period of time, until Vsense settles and is approximately equal to V+, at which point ADC 11 can take a measurement of Vsense A second calibration step can involve switching VA to V-for a relatively long period of time, until Vsense settles and is approximately equal to V-, at which point ADC 11 can take another measurement of Vsense This allows the ADC 11 to measure both V+and V-.
  • Secondly, as shown in Figure 2, while the square wave is switching, ADC 11 readings before and after both edges of the switching waveform may be used to compute the dimensionless quantity Δa: Δα = ΔV Sense / V + V = V 2 V 1 + V 3 V 4 / 2 V + V
    Figure imgb0003
    As a result, both edges of the waveform can be used to measure
    Δ VSense = [(V2-V1)+(V3-V4)] / 2, so that asymmetric responses to the circuit are likely to be canceled out. Alternatively, an average voltage at about the midpoint of the waveform may be used; so that, for example, Δa = ΔVSense/(V+ -V-) = [(V7-V6)+(V7-V8)] / 2(V+ - V-), and ΔVSense = [(V7-V6)+(V7-V8)] / 2. In addition, only differential measurements of the input signal Vin of the ADC 11 can be used. Thus, any offset errors of the buffer amplifier 10 and ADC 11 can be canceled out. Also, Δα is a ratiometric quantity based on measurements using the same signal path. Thus, any gain errors of the ADC 11can also be canceled out.
  • The reference resistor RRef 4 may be optintally chosen to be equal to the geometric mean of the endpoints of the desired range of unknown resistances, taking series resistances Rs 7 into account. For example, if Rs = 100 Ω and Rx varies from 100 Ω to 3000 Ω, then Ry = Rx + 2Rs varies from 300 Ω to 3200 Ω, and Rref should be approximately the square root of (300 Ω • 3200 Ω) = 980 Ω. To measure an unknown resistance in the range of 100k-300k ohms (as in, for example, a column of blood extending from one electrode to another via an arterio-venous fistula), the reference resistor Rref 4 can be changed to approximately 200k ohms and the filter capacitor RF of low pass filter 9 at the input to the buffering amplifier 10 can be removed completely.
  • Because a voltage divider's output is a nonlinear function of its resistance ratio, errors or noise in readings from the ADC 11 produce their lowest fractional error (sensitivity) in the resultant calculation of Ry when it is equal to Rref., and the sensitivity increases the more Ry diverges from the reference resistance Rref. Specifically, it can be shown that the sensitivity in resistance ratio is as follows: S p = 1 / ρ δρ / δΔα = 2 / 1 + Δα 1 Δα = 2 / 1 Δα 2
    Figure imgb0004
    When Ry= Rref, ρ = 1, Δα = 0 and Sρ = 2. Thus, for a change in Δα of 0.001 (0.1% of the ADC full-scale) around this point, the calculated resistance Ry changes by 0.002 or 0.2%. The sensitivity increases as ρ diverges from 1, as shown in Table 1. Table 1
    ρ Δα Sρ
    1 0 2
    2, 0.5 ±0.333 2.25
    4, 0.25 ±0.6 3.13
    5.83, 0.172 ±0.707 4
    10, 0.1 ±0.818 6.05
    20, 0.05 ±0.905 11.03
    Figure 3 shows that the noise/error sensitivity doubles at about a 6:1 ratio of unknown/reference resistance, and triples at a 10:1 ratio. Resistance measurements outside this range may suffer in their increased sensitivity to noise and error.
  • For calibration purposes, a switch SW1 12 can be used to make resistance measurements to calibrate out a point at Rx = 0. Preferably this switch 12 should be placed across the terminals VTA and VTB 3, or as close to the terminals as feasible, which would give a true zero-point calibration. In practice, however, locating the switch 12 close to the terminals VTA and VTB 3 may make the switch 12 prone to external noise and surge voltages, and may introduce DC leakage current into the subject media 1.
  • The series capacitances C1 and C2 6, and the use of square waves are important for unknown resistances that include an electrolytic conductive path. There are at least two reasons for this. First, it may be important in many applications to prevent DC current from flowing through an electrolyte solution or a bodily fluid having similar properties; otherwise electroplating and/or electrolysis of electrodes at the terminals VTA and VTB 3 can occur. In this circuit, the capacitors C1 and C2 6 block DC currents. Furthermore, because the capacitors may allow very small currents to flow (microamps or less), using an alternating square wave voltage may help to limit the average current further.
  • Secondly, in the event that a small electrochemical DC voltage is induced in the subject media 1 (for example, the electrodes in a fluid path may oxidize over time at different rates), this DC voltage can be blocked by the capacitors C1 and C2 6. Because the method for calculating resistance takes differential measurements, any residual DC voltage may be canceled out through the process of calculating the unknown resistance Rx of subject media 1.
  • Vascular disconnect detector
  • With the appropriate modifications of a conductivity measurement circuit such as the one described above, it is possible to detect the conductivity and changes in the conductivity of blood. More specifically, it is possible to detect the change that occurs in the conductivity of a volume of blood when air enters the volume. This situation can occur, for example, when an intravascular access site becomes dislodged in an extracorporeal blood circuit.
  • The circuit shown in Figure 1 can be used to measure the resistance of a volume of fluid in a conductivity cell or conduit 1. For measurements of Rx of a conductivity cell 1 representing the resistance or conductivity of a volume of dialysate solution, a convenient value for the reference resistor RRef 4 can be chosen to be approximately 680 ohms. For measurements of Rx of a conduit 1 representing the resistance or conductivity of a column of blood extending from a first cannula or needle, through an arterio-venous fistula, to a second cannula or needle, a convenient value for the reference resistor RRef 4 can be chosen to be approximately 200k ohms.
  • The advantages of using this circuit to monitor the continuity of a column of a bodily fluid such as blood or plasma include the following:
    • Capacitive coupling to the conductivity cell or conduit 1 blocks DC current which could cause plating and corrosion of electrodes at terminals VTA and VTB;
    • Voltages and current levels are very low and decoupled for patient safety;
    • Current only flows briefly while the measurement is being taken. No current flows between measurements.
  • With the lower reference resistor Rref 4 value (e.g. 680 ohms), this circuit is appropriately configured for dialysate conductivity measurements. With a much higher reference resistor Rref 4 value (e.g. 200k ohms) this circuit is appropriately configured for measuring the resistance between an arterial needle and a venous needle to detect vascular needle dislodgement from an arterio-venous fistula.
  • Electrode placement
  • The continuity of a fluid column leading from a fluid delivery apparatus to a patient's blood vessel or vascular graft can be monitored using the electronic circuit described above. The fluid being delivered may include blood or any electrolyte solution, including dialysate fluid. Although the following discussion will involve a hemodialysis system, the same principles of operation of the invention can apply to any device that is configured to deliver a fluid to a patient via a vascular access. In an embodiment illustrated by Figure 4, the conductivity of a volume of blood or other fluid within a fluid flow circuit 100 of a hemodialysis machine 200 can be monitored electronically, using electrodes on each end of the volume that make direct contact with the blood or other fluid. Using an electrical circuit such as the one shown in Figure 1, one electrode can be connected to the VTA terminal, and the other electrode can be connected to the VTB terminal of the circuit. The voltages applied to the electrodes by the circuit can be sufficiently small (e.g., about 4 volts or less). sufficiently brief, and with DC voltages sufficiently decoupled so as to prevent any harm to the patient. In this example, a fluid flow circuit 100 is shown, including an arterial access needle 102, an arterial catheter tubing 104, an arterial catheter tubing connector 106, arterial blood circuit tubing 108, a transition 110 between the blood circuit tubing 108 and hemodialysis machine 200, a blood pump inlet line 112, a blood pump 114, a blood pump outlet line 116, a dialyzer 118, a dialyzer outlet line 120, air trap 122, a transition 124 between hemodialysis machine 200 and venous blood circuit tubing 126, a venous catheter tubing connector 128, a venous catheter tubing 130, a venous access needle 132, and the intraluminal volume of that portion of the patient's blood vessel or fistula 134 that lies between the arterial access needle 102, and the venous access needle 132. It should be noted that the invention described herein also encompasses circumstances in which the arterial access needle may reside in one blood vessel of a patient, while the venous access needle may reside in a separate blood vessel some distance away from the arterial access site. Furthermore, the circuit described above may be used to monitor the integrity of a vascular access in a fluid delivery system that does not have the venous return line shown in Figure 4. In that case, for example, an electrode at location B could be paired with an electrode in contact with fluid in a dead-end line communicating with a second needle or cannula accessing the blood vessel or vascular graft. In another example, an indwelling hollow cannula or solid trocar in the vascular segment can be equipped with a conductive wire which could then serve as the second electrode in the monitoring system. The vascular segment being accessed may be a surgically constructed arterio-venous fistula, and may also include an artificial conduit such as a Gortex vascular graft. The term `arterial' is used herein to denote the portion of the blood flow circuit that conducts blood away from the patient and toward the hemodialysis machine 200. The term 'venous' is used to denote the portion of the blood flow circuit that conducts blood away from the hemodialysis machine 200 and back toward the patient. The term 'access needle' is used to denote a needle or catheter device that penetrates the patient's vascular segment or fistula. In different embodiments it may be permanently fused or reversibly connected to a corresponding catheter tubing 104, 130.
  • The continuity of any segment of the fluid flow circuit 100 can be monitored by positioning two electrodes in contact with the fluid on either side of the fluid and blood-containing segment of interest. In order to monitor for a disconnection of the arterial access needle 102, or the arterial catheter tubing 104, or the venous access needle 132 or venous catheter tubing 130, one electrode can be placed in continuity with the lumen of the venous side of the blood flow circuit, while a second electrode is placed in continuity with the lumen of the arterial side of the blood flow circuit. In one embodiment, the two electrodes can be positioned on or near the dialysis machine 200, with an electrode in contact with blood upstream of blood pump 110, and a second electrode in contact with blood downstream of the dialyzer 118 and/or air trap 122. For example, the electrodes can be incorporated into transition locations 110 and 124.
  • In another embodiment, one of the electrodes can be positioned to be in contact with the fluid in the fluid flow circuit 100 at a point that is closer to the vascular access site 134 than it is to the equipment (e.g. a dialysis machine) used to deliver fluid flow to the accessed blood vessel or vascular graft. In a preferred embodiment, both electrodes can be positioned to be nearer to the patient's blood vessel or vascular graft than the equipment associated with the dialysis machine 200. This may further reduce electrical interference associated with the dialysis machine 200. An electrode A can be conveniently placed at or near the arterial catheter tubing connector 106 and a second electrode B can be conveniently placed at or near the venous catheter tubing connector 128. In this arrangement, the electrical continuity pathway from the first electrode through the patient's vascular access to the second electrode is much shorter - and the electrical resistance lower- than the pathway extending back toward the dialysis machine 200. In some cases, the access catheters 104 and 130 can be as short as about a foot, whereas the arterial and venous tubings 108 and 126 can be about six feet long. Because of the electrical conductive properties of the fluid in the circuit, the electrical resistance associated with the pathway incorporating tubing 108 and 126, and components of the dialysis machine 200, can be many times greater than the electrical resistance associated with the pathway through the patient's blood vessel or fistula 134.
  • Electrical interference associated with the dialysis machine 200 is thus reduced, and a change in electrical resistance due to an access-related disconnection can more easily be detected. Preferably, the electrodes A and B are positioned to be more than 50% of the distance from the dialysis machine to the patient. More preferably (and more conveniently). the electrodes A and B are located near the last disengageable fluid connection before reaching the patient. In one embodiment of a hemodialysis system, the blood tubing 108 and 126 is approximately 6 feet in length, and the arterial and venous catheter tubes 104, 130 are about two feet or less in length. A convenient location for electrodes A and B would then be at the arterial line and venous line connectors 106,128 (which can be, e.g. Luer type connectors or modifications thereof) that connect the arterial and venous blood circuit tubes 108, 126 with the arterial and venous catheter tubes 104, 130.
  • Connector Electrodes
  • As shown in Figures 5A and 5B, in one embodiment, a blood line connector for the blood circuit of a hemodialysis system may incorporate electrodes that can make contact with any liquid within the lumen of the connector. In one aspect, the electrode can comprise an annular conductive cap 310 placed at the tube-connection or proximal end 302 of any suitable connector, such as, for example connector 300. The electrode is preferably constructed from a durable and non-corrosive material, such as, for example, stainless steel. The distal coupling end 304 of connector 300 can be constructed to make a sealing engagement with a corresponding Luer-type connector of an arterial or venous catheter, for example. The inner annular surface 312 of the cap 310 - in part or in whole - can make contact with any liquid present within the lumen 314 of the connector. As shown in Figure 5B, an O-ring 316 or a suitable sealant can be placed between the cap electrode 310 and the proximal end 302 of the connector to maintain a fluid-tight connection between the connector and any flexible tubing attached to the connector.
  • An elastomeric O-ring may be particularly useful in hemodialysis or other extracorporeal systems in which the blood-carrying components are subjected to disinfection or sterilization using heated liquids. The thermal coefficients of expansion of the plastic components of a connector may be sufficiently different from that of an incorporated metal electrode that a permanent seal may not be preserved after one or more sterilization or disinfection procedures. Adding an elastomeric component such as an O-ring at the junction between an electrode and the connector seat on which it is positioned may preserve the seal by accommodating the different rates of expansion and contraction between the electrode and the connector.
  • As shown in Figure 6, in one embodiment, a conductive electrode 310 (constructed of, e.g., stainless steel) can be incorporated into a portion of a connector 300 (either at its proximal end 302, or alternatively at its distal connecting end 304), over which the end of a flexible tubing 318 can be placed. In this embodiment, the electrode 310 is generally cylindrical, and has a taper 320 on a proximal end to permit an easier slip-fit attachment of the end of a segment of flexible tubing 318 over the outside surface of the electrode 310. As shown in Figure 6, the internal surface of the electrode 310 has an internal ledge 322 that allows the electrode cap 310 to slip over and abut a proximal end 302 of connector 300. Connector 300 can be constructed of any suitable hard material, including metal or more typically a plastic material. The ledge 322 helps to ensure that a smaller diameter inner surface 312 of electrode 310 is properly positioned to make contact with any liquid (e.g. blood) that passes through the lumen 314 of connector 300. The connections between connector 300 and electrode 310, and electrode 310 and the termination of an overlying flexible tubing 318 can be made air tight or permanent with any suitable adhesive compatible with the compositions of the components.
  • To ensure a more secure seal to prevent blood leakage between the connector and electrode, and to limit the area under the electrode where blood elements may migrate and become lodged, an O-ring 316 can be incorporated into the inner surface of electrode 310 near the electrode internal ledge 320. This is seen in enlarged detail in Figure 6. In this example, the O-ring 316 seals between the stainless steel electrode 310 and the distal end 302 of connector 300. A barb element 324 on the proximal end 302 of connector 300 can be incorporated in the connector design in order to hold the stretched end of the flexible tubing 318 onto the proximal end 302 of connector 300. In an embodiment, the electrode 310 is held in place by the portion of the flexible tube that is stretched over both the electrode 310 and the barb 324 of connector 300.
  • A wire 326 can be soldered, welded or otherwise secured onto the outer surface of electrode 310, and can travel under the overlying stretched tubing 318 until exiting more distally along the connector 300. The wire can thus conduct electrical signals to and from the electrode 310 as the internal surface 312 makes contact with the intraluminal fluid (e.g. blood). In the example shown, wire 326 is soldered to a distal portion of electrode 310 and travels under tubing 318, to emerge at the abutment of tubing 318 with a corresponding stop 326 of connector 300.
  • In another embodiment as shown in Figures 7A-7C, a connector 400 as described in U.S. Patent Application Publication No. 2010/0056975 (the contents of which are hereby incorporated by reference) has been modified so that a mid-portion 406 of the connector 400 can incorporate an electrode. Placement of the electrode along the mid-portion 406 of the connector 400 avoids having to alter the distal coupling end 404 of the connector, and avoids any alteration of the interaction between the termination of the flexible tubing and the proximal end 402 of the connector. In this example, the blood line connector 400 is constructed to make two different types of sealing connections on its distal coupling end 404, including an internal screw-type connection 405 for a Luer-type connector of a patient access line, and an external press-in type connection 407 with a dialysis machine port for recirculation of priming and disinfecting fluid through the blood carrying components of a dialysis system. The press-in feature 407 is formed having a frustoconical shape on the outside surface of the distal end 404 of the connector 400, while the Luer-compatible screw-type feature 405 is formed on the corresponding internal surface of the distal end 404 of the connector 400. The outside surface of the frustoconical member is constructed to make seating engagement with the seat of a mating connector of a dialysis machine 200 or other device. A pair of locking arms 408 extending proximally from the distal coupling end 404 of the connector 400 can each have a barbed portion 409 to engage a corresponding locking feature on a mating connector on the dialysis machine, and a finger depression portion 410 to aid in disengaging the barbed portions 409 from the dialysis machine. The barbed portion 409 helps to lock the frustoconical member in sealing engagement with its mating connector on the dialysis machine when making a press-in type of connection. The distal ends of the locking arms can be constructed to attach to the connector via a flange 411 located proximal to the frustoconical portion 407 of the connector 400. The connector 400 has a proximal tubing attachment end 402 to sealingly engage a flexible tube. The tubing attachment end 402 may have one or more barb features 412 to help prevent disengagement of the end of a flexible tube from the connector 400.
  • Figure 7B shows a side view of connector 400, bringing into view an access feature or port 420 that can permit placement of an electrode in direct communication with the lumen of connector 400. In other embodiments, the access feature may house an elastomeric stopper -with or without a septum - to permit sampling of fluid from within the lumen 414 of connector 400 using a syringe with a sharp or blunt needle. Alternatively, the feature may serve as a port to allow connection of another fluid line to the lumen 414 of connector 400.
  • In yet another embodiment, the mid-portion 406 of connector 400 may have two access ports, as shown in the cross-sectional view of Figure 7C. A fluid access port 420a can serve as a sampling port, and an electrode port 420b can serve as an electrode cradle. An elastomeric stopper 422 within sampling port 420a can be shaped to extend to the lumen 414 of connector 400, simultaneously permitting sampling of fluid in the lumen 414 with a needle, while maintaining an air-tight seal. Alternatively, a Luer-type connector having a septated cap or seal can be incorporated into the port, which is capable of connecting with a syringe or catheter having a mating Luer-type connector. An electrode port 420b can serve as a seat or cradle for an electrode 424. In can be press-fit or cemented into position, and sealed with an adhesive, or with an O-ring 416 as shown. A wire 426 can be soldered, welded or otherwise secured onto the outer surface of electrode 424, and can travel proximally toward dialysis machine 200 with the arterial tubing 108 or venous tubing 126 to which connector 400 is attached.
  • In any of the above electrode embodiments, the electrodes may be replaced by a suitably sized thermistor, or combination of a thermistor and electrical conductor, for the additional purpose of monitoring the temperature of the fluid passing through connector 300, 400 or variants thereof.
  • Wire assembly
  • In one embodiment, the wires carrying electrical signals to or from a pair of electrodes on connectors 106, 128 (one on the arterial side and one on the venous side of the blood flow circuit) can travel separate and apart from the blood tubing 108, 126 back toward dialysis machine 200, where they ultimately terminate and connect to a conductivity detecting circuit, such as the conductivity circuit shown in Figure 1. The conductivity circuit, in turn, provides an appropriately configured signal to a processor on the dialysis machine to determine whether a change in fluid conductivity consistent with an access disconnection has occurred. If so, the processor can trigger an alarm condition, or can initiate a shut-down of blood pump 114, and trigger a mechanical occlusion of blood tubing 108 and/or 126, for example.
  • Wires that extend together or separately between the dialysis machine and the patient are at risk of getting tangled, broken or becoming disconnected. Therefore, preferably, each wire 326 or 426 can be attached, fused, or otherwise incorporated into its associated tubing 108, 128. Incorporating a wire into its associated tubing provides a convenient way of protecting the wires and connections, and simplifying the interface between the patient and the dialysis apparatus. Exemplary methods of achieving this are shown in Figures 8A - 8D. In a preferred embodiment, the tubing is comprised of a flexible material (e.g., silicone) that can be formed in an extrusion process. As shown in Figure 8A, a loose wire mesh may be embedded in the flexible silicone tubing as it is formed and extruded, similar to fiber reinforcement of flexible tubing. As shown in Figure 5A. a wire mesh 500 can be embedded within the wall of the flexible tubing 502 during extrusion, in a manner similar to the construction of a a fiber-reinforced tube. As shown in Figure 8B, an insulated wire 504 can be joined to the external surface of its adjacent tubing 506, either during a secondary extrusion process, or a process in which the two structures are joined by an adhesive, for example. As shown in Figure 8C, a second extrusion producing a secondary concentric layer of tubing material 508 can be made to capture a wire running along the external surface of the tubing after the primary extrusion. As shown in Figure 8D. the tubing 510 during formation can also be co-extruded with a wire 512 embedded in the wall of the tubing.
  • In some of the above methods, the resulting tube-wire combination may have a tendency to curl because of the difference in thermal coefficients of expansion between the wire and the silicone material of the tubing. As the material cools after extrusion, the silicone may capture the embedded wire tightly, causing the cooled tube-wire bundle to curl. In a preferred embodiment, the wire lumen of the extrusion die is constructed to be large enough to accommodate a cross-sectional area significantly larger than the cross-sectional area of the wire to be embedded. Then as the silicone cools, the passageway surrounding the wire does not shrink to the point of tightly encasing the wire. A co-extrusion process incorporating an insulated wire can generate a tube-wire bundle as shown in Figure 9. In this example, flexible tubing 514 is a co-extrusion of a fluid-carrying lumen 516 and a wire-carrying lumen 518. Preferably, the wire 520 is multi-stranded for flexibility and durability, and is coated or sheathed in a durable, flexible synthetic insulating material 522, such as, for example, PTFE. A PTFE-based sheath 522 of the stranded wire 520 can sustain the high temperatures associated with the silicone tubing extrusion process, so that its integrity is maintained along the section 524 of the wire that ultimately exits the tubing for connection either to the dialysis machine 200 or the patient line connectors 106, 128. A coating or sheathing may also help prevent the wire from adhering to the side walls of the wire-carrying lumen after extrusion and during cooling.
  • Figure 10 shows a cross-sectional view of an exemplary connector-wire-tubing assembly. The proximal tubing connection end of a connector 400 is shown with the end of a double-lumen tubing 514 attached. The fluid-carrying lumen 516 is press-fit and/or cemented to the proximal end of connector 400, allowing for fluid flow through the central lumen 414 of connector 400. Stranded wire 520 is soldered or otherwise attached to electrode 424, which is in conductive contact with any fluid present within the lumen 414 of connector 400. The non-connecting portion of the wire 520 that travels outside tubing 514 is preferably sheathed in an insulating synthetic coating, such as, for example, PTFE. Optionally, this portion of both the exposed and sheathed wire may also be sealed with a sealant, such as RTV. The sheathed wire 522 enters the wire-carrying lumen 518 of tubing 514 near its termination onto connector 400. The wire/tubing bundle then makes its way toward the dialysis machine 200, where the wire emerges from the tubing to make a connection to a conductivity circuit such as the one shown in Figure 1.
  • Figure 11 shows an exemplary extracorporeal circuit 210 that may be used as a removable, replaceable unit in a hemodialysis apparatus 220 as shown in Figure 12. In this embodiment, the extracorporeal circuit comprises a blood pump cassette 114, dialyzer 118. venous return air trap 122, arterial blood tubing 108, venous blood tubing 126, arterial catheter connector 106, and venous catheter connector 128. The arterial 106 and venous 128 connectors may be of a type similar to the connector 300 shown in Figures 5A and 5B, or similar to the connector 400 shown in Figures 7A - 7C, or variants thereof. The arterial 108 and venous 126 blood tubes may be of a type shown in Figures 8A - 8D, or Figure 9. Wires forming terminal connections to electrodes on connectors 106 and 128 may exit arterial 106 and venous 126 tubes as segments 524A and 524B to make a connection with a connector that ultimately passes the connection through on the dialysis apparatus to terminals associated with a conductivity circuit such as that shown in Figure 1, In the embodiment shown, the connector 526 is mounted to a support structure 212 for the blood pump 114 and air trap 122.
  • Figure 12 shows an exemplary hemodialysis apparatus 220 that is configured to receive the extracorporeal circuit 210 shown in Figure 11. In this illustration, the dialyzer 118 is already mounted onto the apparatus 220. A base unit 220 receives the control ports of a mating blood pump cassette 114. Sets of raceways or tracks 222 help to organize the pair of arterial 106 and venous 126 blood tubes when not extended out and connected with a patient. A connector 224 receives and passes through the connections made between wire segments 524A and 524B and connector 526 to the terminal connections of a conductivity circuit such as that shown in Figure 1. A tubing occluder 226 is positioned to receive venous blood tube 126 after it exits air trap 122, and arterial blood tube 108 before it reaches blood pump cassette 114. The occluder 226 may be actuated pneumatically or electromechanically, for example, whenever an alarm condition occurs that requires cessation of extracorporeal blood flow. A set of arms of occluder 226 can be configured to rotate against the walls of the flexible tubes, constricting or stopping fluid flow within them. Thus, a controller installed within apparatus 220 can receive a signal from a conductivity circuit similar to Figure 1, the signal representing the electrical resistance of the column of fluid or blood between the electrodes mounted on connectors 106 and 128. Because the connectors are positioned much closer fluidically to the patient's blood vessel or fistula 134 than to the blood pump 114, dialyzer 118 and air trap 122, the signal associated with the fluid path through the blood vessel or fistula 134 can discriminate between an intact and an interrupted column of blood or fluid between the connectors 106/128 and the patient's blood vessel or fistula 134. The controller can be programmed to respond to an electrical resistance detected by the conductivity circuit found to exceed a pre-determined value. Depending on the circumstances, the controller may then trigger an alarm to alert the patient to a possible disconnection of blood flow, and may also optionally command the occluder 226 to cease extracorporeal flow to and from the patient.
  • Operation of the disconnect detection circuit
  • Figure 13 shows test results utilizing the disconnect detection circuit described above and shown in Figure 1. In this case, a hemodialysis blood circuit and apparatus was employed that is similar to that disclosed in U.S. Patent Application Publication Nos. 2009/0114582 and 2010/0056975 , (the contents of which are hereby incorporated by reference). The extracorporeal circuit 210 shown in Figure 11, comprises a blood pump 114, dialyzer 118. air trap 122, venous blood circuit tubing 126, and arterial blood circuit tubing 108. Extracorporeal circuit 210 mates to a hemodialysis apparatus 220 similar to the one shown in Figure 12. The blood flow circuit tested included a pair of membrane-based blood pumps arranged on a blood pump cassette 114 shown in Figure 11, a dialyzer 118, a venous return air trap 122, an arterial blood tubing set 108, a venous blood tubing set 126. arterial and venous connectors 106 and 128, and catheter tubing sets 104, 130 connected to vascular access needles 102, 132 as shown in Figure 4. The needles 102, 132 were placed in a container holding anticoagulated bovine blood. The blood tubing set 108 and 126 was approximately six feet long, and the catheter tubing sets 104 and 130 were approximately two feet long or less. The needles were alternately manually placed in or withdrawn from the container during blood flow to simulate disconnection of a needle from a fistula or blood vessel. Periods A, C and F in Figure 13 represent the times during which the needles were submerged in the blood in the container. The electrical resistance measured by the disconnect detection circuit shown in Figure 1 during these periods averaged between 120,000 and 130,000 ohms. Periods B and E in Figure 13 represent the times during which the venous return needle 132 (under positive pressure from the blood pumps) was withdrawn several centimeters above the surface of the blood within the container, forming a stream of blood mixed with air as the blood exited the venous return needle and entered the container of blood below. The electrical resistance measured during these periods averaged between 140,000 and 150,000 ohms. Period D represents the time during which one of the needles was completely removed from the container, creating a fully open electrical circuit. The electrical resistance measured during this period averaged between about 160,000 and 180,000 ohms. Thus a controller can be readily programmed to distinguish the difference in the monitored resistance of the electrical circuit between an uninterrupted and an interrupted flow of blood. These results showed that an interruption of the continuity of the blood between the arterial 102 and venous 132 needles can reliably produce a detectible change in the measured electrical resistance between two electrodes when placed relatively closer to the arterial and venous access sites than to the blood processing components 114, 118 and 122 of the extracorporeal blood circuit. Furthermore, even a partial interruption of the continuity of blood flow (as in the streaming of blood through air) can be reliably detected, albeit with a smaller change in the measured electrical resistance.
  • The following numbered paragraphs provide further disclosure of the present subject matter.
  1. 1. A system for detecting the disconnection of a vascular access device from a blood vessel or vascular graft, comprising:
    • a fluid delivery device for providing fluid through a first conduit into a first site of the blood vessel or graft;
    • a first electrode in contact with the lumen of the first conduit;
    • a second electrode in fluid communication with a second site of the blood vessel or graft;
    • an electronic circuit connected to the first and second electrodes, and configured to deliver a control signal to the first and second electrodes in order to measure the electrical resistance of a fluid between the first and second electrodes, wherein
    • at least one of the electrodes is located closer to the blood vessel or graft than to the fluid delivery device.
  2. 2. The system of para. 1, wherein the fluid delivery device comprises a pump.
  3. 3. The system of para. 1, wherein the fluid delivery device comprises a hemodialysis blood flow circuit.
  4. 4. The system of para. 1, wherein the second electrode is in contact with the lumen of a second conduit accessing the blood vessel or graft at the second site.
  5. 5. The system of para. 4, wherein the second conduit comprises part of a fluid flow path from the blood vessel or graft to the fluid delivery device.
  6. 6. The system of para. 5, wherein the first conduit comprises a first connector connecting a first vascular access catheter to a first tube segment, the second conduit comprises a second connector connecting a second vascular access catheter to a second tube segment, and the first and second vascular access catheters are shorter than the first and second tube segments.
  7. 7. The system of para. 6, wherein the first connector includes the first electrode and the second connector includes the second electrode.
  8. 8. The system of para. 1, wherein the first conduit comprises a double lumen flexible tube having a first lumen for carrying the fluid, and a second lumen for carrying a wire connecting the first electrode to the electronic circuit.
  9. 9. The system of para. 1, further comprising a controller configured to receive a signal from the electronic circuit, the signal representing the electrical resistance between the electrodes, wherein the controller is programmed to trigger an alert signal when the electrical resistance value exceeds a pre-determined threshold.
  10. 10. The system of para. 9, wherein the alert signal comprises an electrical command to a tubing occluder apparatus, wherein the tubing occluder apparatus includes a mechanical occluder arranged and configured to occlude the conduit.
  11. 11. An apparatus for monitoring the continuity between a vascular access device and a blood vessel or vascular graft segment, comprising:
    • a first and second vascular connector, the first connector being attached on a proximal end to a distal end of a fluid-carrying lumen of a first double-lumen tube, and the second connector being attached on a proximal end to a distal end of a fluid-carrying lumen of a second double-lumen tube,
    • the first connector comprising a first electrode in contact with a lumen of the first connector and electrically connected to a wire within a wire-carrying lumen of the first double-lumen tube, and the second connector comprising a second electrode in contact with a lumen of the second connector and electrically connected to a wire within a wire-carrying lumen of the second double-lumen tube, wherein,
    • the wire within the first double-lumen tube and the wire within the second double- lumen tube are each connected to an electrical connector at a proximal end of the double-lumen tubes.
  12. 12. The apparatus of para. 11, wherein a distal end of each connector comprises a locking member for providing a reversible, air-tight connection between the connector and a mating connector of a vascular catheter.
  13. 13. The apparatus of para. 12, wherein a proximal end of the fluid-carrying lumen of the first double-lumen tube is connected to a blood pump, and a proximal end of the fluid-carrying lumen of the second double-lumen tube is connected to an air trap.
  14. 14. The apparatus of para. 13, wherein the air trap and the blood pump are configured for reversible connection to a dialyzer cartridge.
  15. 15. A vascular connector comprising a proximal fluid connection end, a distal fluid connection end, and an electrode configured to electrically connect a fluid-carrying lumen of the connector with a wire external to the vascular connector.
  16. 16. The vascular connector of para. 15, wherein the proximal fluid connection end is configured to fluidly connect with an end of a flexible tube, and the distal fluid connection end is configured to reversibly connect with a mating connector of a vascular catheter.
  17. 17. The vascular connector of para. 15, wherein the electrode is installed in a conduit on the electrode connecting the lumen of the connector with an external surface of the connector.
  18. 18. The vascular connector of para. 17, wherein the electrode is lodged within the conduit, forming an air-tight seal between the lumen and the external surface of the connector.
  19. 19. The vascular connector of para. 18, wherein an elastomeric member is installed between the electrode and the conduit, contributing to the air-tight seal between the lumen and the external surface of the connector.
  20. 20. An electrical circuit for measuring the resistance of a liquid between a first and second electrode, the first electrode connected to a first terminal of the electrical circuit, and the second electrode connected to a second terminal of the electrical circuit, comprising:
    • a capacitor C1 connected on a first end to the first terminal and a capacitor C2 connected on a first end to the second terminal;
    • a known reference resistance Rref connected on a first end to a second end of capacitor C1;
    • switching means for connecting either;
      1. a) a first reference voltage V+ to a second end of Rref, and a lower second reference voltage V- to a second end of C2 to form a first switch configuration or;
      2. b) the first reference voltage V+ to the second end of C2 and the lower second reference voltage V- to the second end of Rref to form a second switch configuration; and measuring means for measuring a voltage Vsense at the connection between C1 and Rref; wherein
    • the electrical circuit is configured to determine the value of the resistance of the liquid based on the known reference resistance Rref and the observed voltage Vsense for each of the first and second switch configurations.
  21. 21. The electrical circuit of para. 20, wherein the resistance Rref is chosen to permit conductivity measurement of an electrolyte solution suitable for intravascular infusion.
  22. 22. The electrical circuit of para. 21, wherein the electrolyte solution comprises dialysate solution.
  23. 23. The electrical circuit of para. 20, wherein the resistance Rref is chosen to permit measurement of the resistance of a volume of blood between the first and second electrodes.

Claims (22)

  1. An electrical circuit for measuring the resistance of a liquid between a first and second electrode, the first electrode connected to a first terminal Vta (3) of the electrical circuit, and the second electrode connected to a second terminal Vtb (3) of the electrical circuit, comprising:
    a capacitor C1 connected on a first end to the first terminal and a capacitor C2 connected on a first end to the second terminal;
    a known reference resistance Rref connected on a first end to a second end of capacitor C1;
    switching means (2) for connecting either;
    a) a first reference voltage V+ to a second end of Rref, and a lower second reference voltage V- to a second end of C2 to form a first switch configuration or;
    b) the first reference voltage V+ to the second end of C2 and the lower second reference voltage V- to the second end of Rref to form a second switch configuration; and
    measuring means (10, 11) for measuring a voltage Vsense at the connection between C1 and Rref; wherein
    the electrical circuit is configured to determine the value of the resistance of the liquid based on the known reference resistance Rref and the observed voltage Vsense for each of the first and second switch configurations.
  2. The electrical circuit of claim 1, wherein the resistance Rref is chosen to permit conductivity measurement of an electrolyte solution suitable for intravascular infusion.
  3. The electrical circuit of claim 2, wherein the electrolyte solution comprises dialysate solution.
  4. The electrical circuit of claim 1, wherein the resistance Rref is chosen to permit measurement of the resistance of a volume of blood between the first and second electrodes.
  5. A system for detecting the disconnection of a vascular access device from a blood vessel or vascular graft, comprising:
    a fluid delivery device (200) for providing liquid through a first conduit (126) into a first site of the blood vessel or graft, and for receiving fluid through a second conduit (108) from a second site of the blood vessel or graft;
    wherein the first electrode is in fluid communication with a lumen of the first conduit;
    wherein the second electrode is in fluid communication with a lumen of the second conduit;
    the system further comprising the electrical circuit of any of claims 1 to 4.
  6. The system of claim 5, wherein the first and second electrodes are located closer to the blood vessel or graft than to the fluid delivery device.
  7. The system of claim 5 or 6, further comprising a low pass filter (9) connected between the measuring means and said connection between C1 and Rref where Vsense is measured.
  8. The system of claim 7, wherein the low pass filter includes a resistor and capacitor to filter high-frequency noise.
  9. The system of any of claims 5 to 8, wherein the measuring means includes a buffer amplifier (10) and an analog-to-digital converter (11).
  10. The system of any of claims 5 to 9, wherein the switching means includes first and second multiplexers.
  11. The system of claim 10, wherein the first and second multiplexers are driven by respective alternating binary control signals.
  12. The system of claim 10 or 11, wherein the first and second multiplexers each have a first input connected to the first reference voltage V+ and a second input connected to the second reference voltage V-.
  13. The system of any of claims 5 to 12, further comprising a voltage divider that creates the first and second reference voltages.
  14. The system of claim 13, wherein the voltage divider is provided with a main reference voltage Vref from which the voltage divider creates the first and second reference voltages.
  15. The system of claim 14, wherein the first reference voltage is greater than the second reference voltage, and wherein the first reference voltage is close to the main reference voltage Vref and the second reference voltage is close to a ground reference voltage.
  16. The system of any of claims 5 to 15, wherein the switching means is operated to alternate between the first and second switch configurations and the measuring means is arranged to measure Vsense before and after each time the switching network changes between the first and second switch configurations.
  17. The system of any of claims 5 to 16, wherein the resistance of resistor Rref is selected to be a geometric mean of endpoints of a range of resistances to be determined by the electrical circuit.
  18. The system of claim 17, wherein the range of resistances to be determined by the electrical circuit includes series resistances Rs.
  19. The system of any of claims 5 to 18, further comprising a calibration switch (12).
  20. The system of any of claims 5 to 19, wherein the capacitors C1 and C2 block DC current from passing through a path between the first and second terminals.
  21. The system of any of claims 5 to 20, wherein each of said first and second electrodes is electrically connected to a corresponding one of the first and second terminals of the electronic circuit through a wire located in a second lumen of a double lumen tube, a first lumen of said double lumen tube configured to carry blood between the fluid delivery device and the first or second site.
  22. The system of claim 5 wherein the first and second conduits are flexible tubes and the system further comprises a first connector configured to connect the first conduit to a first catheter, and a second connector configured to connect the second conduit to a second catheter, each connector having an electrode in fluid communication with a lumen of said connector.
EP16168110.1A 2009-10-30 2010-10-29 Apparatus and method for detecting disconnection of an intravascular access device Pending EP3072545A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US25673509P true 2009-10-30 2009-10-30
EP10795810.0A EP2493526B1 (en) 2009-10-30 2010-10-29 Apparatus and method for detecting disconnection of an intravascular access device

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
EP10795810.0A Division EP2493526B1 (en) 2009-10-30 2010-10-29 Apparatus and method for detecting disconnection of an intravascular access device

Publications (1)

Publication Number Publication Date
EP3072545A1 true EP3072545A1 (en) 2016-09-28

Family

ID=43587253

Family Applications (2)

Application Number Title Priority Date Filing Date
EP16168110.1A Pending EP3072545A1 (en) 2009-10-30 2010-10-29 Apparatus and method for detecting disconnection of an intravascular access device
EP10795810.0A Active EP2493526B1 (en) 2009-10-30 2010-10-29 Apparatus and method for detecting disconnection of an intravascular access device

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP10795810.0A Active EP2493526B1 (en) 2009-10-30 2010-10-29 Apparatus and method for detecting disconnection of an intravascular access device

Country Status (7)

Country Link
US (2) US20110105877A1 (en)
EP (2) EP3072545A1 (en)
JP (3) JP2013509271A (en)
CN (2) CN104841030B (en)
CA (1) CA2779296C (en)
MX (2) MX353433B (en)
WO (1) WO2011053810A2 (en)

Families Citing this family (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
MX2008013266A (en) 2006-04-14 2008-10-27 Deka Products Lp Systems, devices and methods for fluid pumping, heat exchange, thermal sensing, and conductivity sensing.
US8366316B2 (en) 2006-04-14 2013-02-05 Deka Products Limited Partnership Sensor apparatus systems, devices and methods
US20090107335A1 (en) * 2007-02-27 2009-04-30 Deka Products Limited Partnership Air trap for a medical infusion device
US8562834B2 (en) 2007-02-27 2013-10-22 Deka Products Limited Partnership Modular assembly for a portable hemodialysis system
US8491184B2 (en) 2007-02-27 2013-07-23 Deka Products Limited Partnership Sensor apparatus systems, devices and methods
US8393690B2 (en) 2007-02-27 2013-03-12 Deka Products Limited Partnership Enclosure for a portable hemodialysis system
US8042563B2 (en) 2007-02-27 2011-10-25 Deka Products Limited Partnership Cassette system integrated apparatus
US9028691B2 (en) 2007-02-27 2015-05-12 Deka Products Limited Partnership Blood circuit assembly for a hemodialysis system
KR101505213B1 (en) 2007-02-27 2015-03-30 데카 프로덕츠 리미티드 파트너쉽 Hemodialysis System and Methods
US7967022B2 (en) 2007-02-27 2011-06-28 Deka Products Limited Partnership Cassette system integrated apparatus
US8409441B2 (en) 2007-02-27 2013-04-02 Deka Products Limited Partnership Blood treatment systems and methods
US8357298B2 (en) 2007-02-27 2013-01-22 Deka Products Limited Partnership Hemodialysis systems and methods
US8425471B2 (en) 2007-02-27 2013-04-23 Deka Products Limited Partnership Reagent supply for a hemodialysis system
US9308307B2 (en) 2007-09-13 2016-04-12 Fresenius Medical Care Holdings, Inc. Manifold diaphragms
US8597505B2 (en) 2007-09-13 2013-12-03 Fresenius Medical Care Holdings, Inc. Portable dialysis machine
US9358331B2 (en) 2007-09-13 2016-06-07 Fresenius Medical Care Holdings, Inc. Portable dialysis machine with improved reservoir heating system
US9199022B2 (en) 2008-09-12 2015-12-01 Fresenius Medical Care Holdings, Inc. Modular reservoir assembly for a hemodialysis and hemofiltration system
US8105487B2 (en) 2007-09-25 2012-01-31 Fresenius Medical Care Holdings, Inc. Manifolds for use in conducting dialysis
US8040493B2 (en) 2007-10-11 2011-10-18 Fresenius Medical Care Holdings, Inc. Thermal flow meter
WO2009073567A1 (en) 2007-11-29 2009-06-11 Xcorporeal. Inc. System and method for conducting hemodialysis and hemofiltration
MX340256B (en) * 2008-01-23 2016-06-30 Deka Products Lp Fluid line autoconnect apparatus and methods for medical treatment system.
US8863772B2 (en) * 2008-08-27 2014-10-21 Deka Products Limited Partnership Occluder for a medical infusion system
AU2009302327C1 (en) 2008-10-07 2015-09-10 Fresenius Medical Care Holdings, Inc. Priming system and method for dialysis systems
BRPI0921637A2 (en) 2008-10-30 2016-01-05 Fresenius Med Care Hldg Inc modular portable dialysis system
US8240636B2 (en) 2009-01-12 2012-08-14 Fresenius Medical Care Holdings, Inc. Valve system
US8535522B2 (en) 2009-02-12 2013-09-17 Fresenius Medical Care Holdings, Inc. System and method for detection of disconnection in an extracorporeal blood circuit
AU2010278894B2 (en) 2009-07-30 2014-01-30 Tandem Diabetes Care, Inc. Infusion pump system with disposable cartridge having pressure venting and pressure feedback
EP3072545A1 (en) 2009-10-30 2016-09-28 DEKA Products Limited Partnership Apparatus and method for detecting disconnection of an intravascular access device
MX2013000212A (en) 2010-07-07 2013-05-09 Deka Products Lp Medical treatment system and methods using a plurality of fluid lines.
CA2837200A1 (en) 2011-05-24 2012-11-29 Deka Products Limited Partnership Hemodialysis system
US9999717B2 (en) 2011-05-24 2018-06-19 Deka Products Limited Partnership Systems and methods for detecting vascular access disconnection
EP3263150A1 (en) 2011-05-24 2018-01-03 DEKA Products Limited Partnership Blood treatment systems and methods
US9364655B2 (en) 2012-05-24 2016-06-14 Deka Products Limited Partnership Flexible tubing occlusion assembly
US9157786B2 (en) 2012-12-24 2015-10-13 Fresenius Medical Care Holdings, Inc. Load suspension and weighing system for a dialysis machine reservoir
US9173998B2 (en) 2013-03-14 2015-11-03 Tandem Diabetes Care, Inc. System and method for detecting occlusions in an infusion pump
US9421329B2 (en) 2013-03-15 2016-08-23 Tandem Diabetes Care, Inc. Infusion device occlusion detection system
US9354640B2 (en) 2013-11-11 2016-05-31 Fresenius Medical Care Holdings, Inc. Smart actuator for valve
JP6487753B2 (en) * 2015-04-01 2019-03-20 日機装株式会社 Medical devices
CN109310813A (en) 2016-04-13 2019-02-05 巴兹莱医疗中心的基础设施及卫生服务的医学研发基金会 Intravascular path device is displaced alert device and method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4656427A (en) * 1985-02-05 1987-04-07 Dauphinee Thomas M Liquid conductivity measuring circuit
US5469070A (en) * 1992-10-16 1995-11-21 Rosemount Analytical Inc. Circuit for measuring source resistance of a sensor
DE10206666A1 (en) * 2002-02-18 2003-08-28 Siemens Ag Determining measuring resistance of sensor element involves applying measuring voltage over sensor element, varying reference voltage, and comparing measuring voltage with reference voltage
US20090088683A1 (en) * 2007-10-01 2009-04-02 Baxter International Inc. Adaptive algorithm for access disconnect detection
US20090114582A1 (en) 2007-02-27 2009-05-07 Deka Products Limited Partnership Enclosure for a portable hemodialysis system
US20100056975A1 (en) 2008-08-27 2010-03-04 Deka Products Limited Partnership Blood line connector for a medical infusion device

Family Cites Families (430)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1693526A (en) 1927-06-15 1928-11-27 Charles S Owens Hinge
US2529028A (en) 1947-07-31 1950-11-07 Landon Standard Pools Chemical feeder
US2741099A (en) 1953-02-11 1956-04-10 Brewer Titchener Corp Apparatus for indicating and controlling the temperature of products within predetermined limits
US2816514A (en) 1954-09-17 1957-12-17 Designers For Industry Inc Vibratory pump
US3016563A (en) * 1959-03-04 1962-01-16 Jong George Edward De Combined hinge and catch
US3200648A (en) 1963-02-04 1965-08-17 William H Waggaman Method and apparatus for comparing smoking properties of various cigarettes
US3508656A (en) 1968-04-10 1970-04-28 Milton Roy Co Portable dialysate supply system
US3539081A (en) 1968-07-05 1970-11-10 Jet Spray Cooler Inc Valve for beverage dispensers
US3656873A (en) 1970-11-06 1972-04-18 Peter Schiff Pulsatile by-pass blood pump
US3759483A (en) 1971-05-14 1973-09-18 T Baxter Fluid actuated control valve
USRE27849E (en) 1971-11-30 1973-12-25 Dynamic action valveless artifjcial heart utilizing dual fluid oscillator
FR2188146B1 (en) 1972-06-02 1976-08-06 Instr Con Analyse
US3847809A (en) 1972-07-03 1974-11-12 David Kopf Syst Proportioning system
US3827561A (en) 1972-09-20 1974-08-06 Milton Roy Co Deaerator for dialysis system
US3882861A (en) 1973-09-24 1975-05-13 Vital Assists Auxiliary control for a blood pump
US3936729A (en) * 1974-02-28 1976-02-03 Petrolite Corporation Conductivity measurement probe
JPS5911864B2 (en) 1975-07-14 1984-03-19 Takeda Chemical Industries Ltd
FR2326235B1 (en) 1975-10-01 1979-04-20 Renault
US4085047A (en) 1976-09-16 1978-04-18 Thompson Lester E Blood leak detector
US4133312A (en) * 1976-10-13 1979-01-09 Cordis Dow Corp. Connector for attachment of blood tubing to external arteriovenous shunts and fistulas
US4155852A (en) 1976-11-19 1979-05-22 Halbert Fischel Low leakage current medical instrument
US4096859A (en) 1977-04-04 1978-06-27 Agarwal Mahesh C Apparatus for peritoneal dialysis
US4161264A (en) 1977-06-17 1979-07-17 Johnson Bryan E Fluid metering and mixing device having inlet and outlet valves
FR2405610B1 (en) * 1977-10-07 1980-08-01 Leboeuf Lola
DE2838414C2 (en) 1978-09-02 1984-10-31 Fresenius Ag, 6380 Bad Homburg, De
DE2843756C3 (en) 1978-10-06 1988-05-26 Vaillant, Michael, 4600 Dortmund, De
US4439188A (en) * 1980-09-15 1984-03-27 Baxter Travenol Laboratories, Inc. Tube connector
US4227814A (en) 1979-02-01 1980-10-14 Baxter Travenol Laboratories, Inc. Optical density detector
US4266814A (en) 1979-03-23 1981-05-12 Vfp Corporation Plastic tube adapter
US4362156A (en) 1979-04-18 1982-12-07 Riverain Corporation Intravenous infusion assembly
US4282099A (en) 1979-12-10 1981-08-04 Jones John L Integral partitioned hemodialysis unit
US4490254A (en) 1980-02-25 1984-12-25 Bentley Laboratories, Inc. Blood filter
FR2487679B1 (en) 1980-08-01 1985-07-12 Hospal Sodip artificial kidney - regulation of the pressure of the dialysis liquid
US5033513A (en) 1980-10-29 1991-07-23 Proprietary Technology, Inc. Swivelable quick connector assembly
US5782508A (en) 1980-10-29 1998-07-21 Proprietary Technologies, Inc. Swivelable quick connector assembly
US4398908A (en) 1980-11-28 1983-08-16 Siposs George G Insulin delivery system
US4322054A (en) * 1980-12-29 1982-03-30 Red Valve Company, Inc. Pinch valve
US4369781A (en) * 1981-02-11 1983-01-25 Sherwood Medical Industries Inc. Luer connector
US4574876A (en) * 1981-05-11 1986-03-11 Extracorporeal Medical Specialties, Inc. Container with tapered walls for heating or cooling fluids
US4731072A (en) * 1981-05-11 1988-03-15 Mcneilab, Inc. Apparatus for heating or cooling fluids
FR2507481B1 (en) 1981-06-16 1985-06-14 Hospal Sodip artificial kidney with integrated circuits
US4411783A (en) 1981-12-23 1983-10-25 Shiley Incorporated Arterial blood filter with improved gas venting
US4441357A (en) 1982-03-04 1984-04-10 Meadox Instruments, Inc. Pressure monitoring and leak detection method and apparatus
US4479761A (en) 1982-12-28 1984-10-30 Baxter Travenol Laboratories, Inc. Actuator apparatus for a prepackaged fluid processing module having pump and valve elements operable in response to externally applied pressures
US4479760A (en) 1982-12-28 1984-10-30 Baxter Travenol Laboratories, Inc. Actuator apparatus for a prepackaged fluid processing module having pump and valve elements operable in response to applied pressures
US4479762A (en) 1982-12-28 1984-10-30 Baxter Travenol Laboratories, Inc. Prepackaged fluid processing module having pump and valve elements operable in response to applied pressures
US4492258A (en) * 1983-02-18 1985-01-08 Whitman Medical Corporation Sterile urine specimen collection
US4623334A (en) 1983-03-07 1986-11-18 Vanderbilt University Intravenous drug infusion apparatus
US4501405A (en) * 1983-06-21 1985-02-26 Bunnell Life Systems, Inc. Frictionless valve/pump
DE3328744A1 (en) 1983-08-09 1985-02-28 Fresenius Ag Haemodialysis device
JPS6077782U (en) 1983-11-01 1985-05-30
US4664891A (en) 1984-07-23 1987-05-12 Renal Systems, Inc. Dialysis solution preparation from prepackaged dry chemicals
US4585442A (en) 1984-07-26 1986-04-29 Ivy Medical, Inc. Miniature intravenous infusion rate controller
DE3582772D1 (en) 1984-09-06 1991-06-13 Genshiro Ogawa Electronically controlled heater for infusionsfluessigkeiten.
GB8424101D0 (en) 1984-09-24 1984-10-31 Vi Tal Hospital Products Ltd Air-in-line detector
US4718022A (en) * 1985-02-21 1988-01-05 Cochran Michael J Dialysis machine which anticipates concentration changes
US4695385A (en) 1985-04-29 1987-09-22 Colorado Medical, Inc. Dialyzer reuse system
US4745279A (en) 1986-01-02 1988-05-17 American Hospital Supply Corporation Hematocrit measuring apparatus
US5178182A (en) * 1986-03-04 1993-01-12 Deka Products Limited Partnership Valve system with removable fluid interface
US4778451A (en) 1986-03-04 1988-10-18 Kamen Dean L Flow control system using boyle's law
US5575310A (en) 1986-03-04 1996-11-19 Deka Products Limited Partnership Flow control system with volume-measuring system using a resonatable mass
US4976162A (en) 1987-09-03 1990-12-11 Kamen Dean L Enhanced pressure measurement flow control system
US4826482A (en) 1986-03-04 1989-05-02 Kamen Dean L Enhanced pressure measurement flow control system
US5074838A (en) 1988-11-07 1991-12-24 Kr Phi Yer Karl K K Extracorporal thermo-therapy device and method for curing diseases using penetrants
SE459641B (en) 1986-03-24 1989-07-24 Gambro Ab The detector system foer control of a foer conducting blood alternating with a vaesentligen faergloes vaetska intended vaetskeslang
US4828543A (en) 1986-04-03 1989-05-09 Weiss Paul I Extracorporeal circulation apparatus
US5160325A (en) 1986-10-06 1992-11-03 C. R. Bard, Inc. Catheter with novel lumens shapes
US4784495A (en) 1987-02-06 1988-11-15 Gambro Ab System for preparing a fluid intended for a medical procedure by mixing at least one concentrate in powder form with water
US4927411A (en) 1987-05-01 1990-05-22 Abbott Laboratories Drive mechanism for disposable fluid infusion pumping cassette
NL8701233A (en) * 1987-05-22 1988-12-16 Medistad Holland Blood Warmer.
US5088515A (en) * 1989-05-01 1992-02-18 Kamen Dean L Valve system with removable fluid interface
US4822343A (en) 1987-09-21 1989-04-18 Louise Beiser Blood collection device with ejectable tips
US4833329A (en) 1987-11-20 1989-05-23 Mallinckrodt, Inc. System for generating and containerizing radioisotopes
DE68916876D1 (en) * 1988-01-25 1994-08-25 Baxter Int Pre-slit injection device and conical cannula.
SE465404B (en) 1988-03-03 1991-09-09 Gambro Ab dialysis System
US4863461A (en) 1988-03-21 1989-09-05 Symbion, Inc. Artificial ventricle
EP0336993B1 (en) 1988-04-13 1993-07-21 Med-Tech Inc. Method of controlling amount of removed water by ultrafiltration and control device for controlling amount of removed water by ultrafiltration in hemodialysis
US4950235A (en) 1988-05-10 1990-08-21 Pacesetter Infusion, Ltd. Container-side occlusion detection system for a medication infusion system
US4884065A (en) 1988-06-13 1989-11-28 Pacesetter Infusion, Ltd. Monitor for detecting tube position and air bubbles in tube
US4976729A (en) 1988-08-15 1990-12-11 University Of Utah Research Foundation Elliptical artificial heart
US5110447A (en) 1988-09-12 1992-05-05 Kasten, Eadie Technology Ltd. Process and apparatus for partial upgrading of a heavy oil feedstock
DE3837498C2 (en) * 1988-11-04 1990-10-18 Fresenius Ag, 6380 Bad Homburg, De
US5061241A (en) 1989-01-19 1991-10-29 Stephens Jr Harry W Rapid infusion device
DE3907735A1 (en) * 1989-03-10 1990-09-20 Bran & Luebbe Diaphragm pump with free-swinging metal membrane
IE66526B1 (en) 1989-03-17 1996-01-24 Baxter Int A pre-slit injection site usable with a blunt cannula
US5702371A (en) 1989-07-24 1997-12-30 Venetec International, Inc. Tube fitting anchoring system
US5423738A (en) 1992-03-13 1995-06-13 Robinson; Thomas C. Blood pumping and processing system
DE3938662C2 (en) * 1989-11-21 1992-05-27 Fresenius Ag, 6380 Bad Homburg, De
US5062774A (en) 1989-12-01 1991-11-05 Abbott Laboratories Solution pumping system including disposable pump cassette
US5125069A (en) 1989-12-22 1992-06-23 Netherlands Health Sciences Blood warmer
US5110477A (en) 1990-02-13 1992-05-05 Howard David B Dialyzer clearance check system
US5278072A (en) * 1990-04-26 1994-01-11 Minnesota Mining And Manufacturing Company Calibration system and housing
US5351686A (en) 1990-10-06 1994-10-04 In-Line Diagnostics Corporation Disposable extracorporeal conduit for blood constituent monitoring
US5105981A (en) 1990-11-19 1992-04-21 Thomas Gehman Selectively shakeable freestanding particulate matter reservoir
US5308320A (en) * 1990-12-28 1994-05-03 University Of Pittsburgh Of The Commonwealth System Of Higher Education Portable and modular cardiopulmonary bypass apparatus and associated aortic balloon catheter and associated method
US5116316A (en) 1991-02-25 1992-05-26 Baxter International Inc. Automatic in-line reconstitution system
US5245693A (en) 1991-03-15 1993-09-14 In-Touch Products Co. Parenteral fluid warmer apparatus and disposable cassette utilizing thin, flexible heat-exchange membrane
US5381510A (en) * 1991-03-15 1995-01-10 In-Touch Products Co. In-line fluid heating apparatus with gradation of heat energy from inlet to outlet
US5326476A (en) 1991-04-19 1994-07-05 Althin Medical, Inc. Method and apparatus for kidney dialysis using machine with programmable memory
US5247434A (en) 1991-04-19 1993-09-21 Althin Medical, Inc. Method and apparatus for kidney dialysis
US5486286A (en) * 1991-04-19 1996-01-23 Althin Medical, Inc. Apparatus for performing a self-test of kidney dialysis membrane
US5336165A (en) 1991-08-21 1994-08-09 Twardowski Zbylut J Artificial kidney for frequent (daily) Hemodialysis
US5902476A (en) 1991-08-21 1999-05-11 Twardowski; Zbylut J. Artificial kidney for frequent (daily) hemodialysis
US5290239A (en) 1991-09-26 1994-03-01 Baxter International, Inc. Intravenous tube safety apparatus
WO1993012825A1 (en) * 1991-12-20 1993-07-08 Abbott Laboratories Automated drug infusion system with autopriming
IT1250558B (en) 1991-12-30 1995-04-20 Hospal Dasco Spa Dialysis machine with control of security and related safety control method.
US5267956A (en) 1992-02-05 1993-12-07 Alcon Surgical, Inc. Surgical cassette
US5411472A (en) 1992-07-30 1995-05-02 Galen Medical, Inc. Low trauma blood recovery system
US5476368A (en) 1992-08-20 1995-12-19 Ryder International Corporation Sterile fluid pump diaphragm construction
US5476444A (en) 1992-09-04 1995-12-19 Idt, Inc. Specialized perfusion protocol for whole-body hyperthermia
SE505801C2 (en) 1992-09-25 1997-10-13 Atlas Copco Tools Ab Cabinets for housing electronic equipment connectable to the equipment or power tools
EP0662844B1 (en) 1992-10-01 1998-03-11 American Sterilizer Company Accumulator-based liquid metering system and method
DE4336336A1 (en) 1992-11-23 1994-05-26 Lang Volker Kasetteninfusionssystem
DE4239937C2 (en) 1992-11-27 1995-08-24 Fresenius Ag Procedure for determining the operability of a partial device of a hemodialysis machine, and device for carrying out this method
US5306242A (en) 1992-12-15 1994-04-26 Abbott Laboratories Recirculation through plural pump cassettes for a solution compounding apparatus
GB2273533B (en) 1992-12-18 1996-09-25 Minnesota Mining & Mfg Pumping cassette with integral manifold
CA2145295A1 (en) * 1992-12-30 1994-07-21 Kent D. Abrahamson Diaphragm for solution pumping system
US5441636A (en) 1993-02-12 1995-08-15 Cobe Laboratories, Inc. Integrated blood treatment fluid module
US5431626A (en) 1993-03-03 1995-07-11 Deka Products Limited Partnership Liquid pumping mechanisms for peritoneal dialysis systems employing fluid pressure
US5474683A (en) 1993-03-03 1995-12-12 Deka Products Limited Partnership Peritoneal dialysis systems and methods employing pneumatic pressure and temperature-corrected liquid volume measurements
DE69413166T2 (en) 1993-03-03 1999-05-12 Deka Products Lp Device for peritonaldialyse equipped with a Liquid distribution for air separation and pumping cartridge.
US5324422A (en) 1993-03-03 1994-06-28 Baxter International Inc. User interface for automated peritoneal dialysis systems
US5438510A (en) 1993-03-03 1995-08-01 Deka Products Limited Partnership User interface and monitoring functions for automated peritoneal dialysis systems
US5350357A (en) 1993-03-03 1994-09-27 Deka Products Limited Partnership Peritoneal dialysis systems employing a liquid distribution and pumping cassette that emulates gravity flow
US5413566A (en) 1993-03-16 1995-05-09 Micropump Corporation Line clamp
US5410255A (en) 1993-05-07 1995-04-25 Perma-Pipe, Inc. Method and apparatus for detecting and distinguishing leaks using reflectometry and conductivity tests
US5385540A (en) * 1993-05-26 1995-01-31 Quest Medical, Inc. Cardioplegia delivery system
US5645531A (en) 1993-05-26 1997-07-08 Quest Medical, Inc. Constant pressure blood mixture delivery system and method
JP2576760B2 (en) 1993-06-08 1997-01-29 日本電気株式会社 Micro field emission cold cathode and a manufacturing method thereof
US5349896A (en) 1993-06-14 1994-09-27 W. L. Gore & Associates, Inc. Pump diaphragm
US5398851A (en) 1993-08-06 1995-03-21 River Medical, Inc. Liquid delivery device
US5395316A (en) * 1993-08-11 1995-03-07 Med-Pro Design, Inc. Triple lumen catheter
US5441343A (en) 1993-09-27 1995-08-15 Topometrix Corporation Thermal sensing scanning probe microscope and method for measurement of thermal parameters of a specimen
US5420962A (en) 1993-10-25 1995-05-30 Bakke; Allan P. Convection blood warming system with disposable flattened tube envelope having vent incorporating a hydrophobic filter
GB9325591D0 (en) 1993-12-14 1994-02-16 Somerset Technical Lab Ltd Leakage detection
US5482440A (en) * 1993-12-22 1996-01-09 Baxter Int Blood processing systems using a peristaltic pump module with valve and sensing station for operating a peristaltic pump tube cassette
US5680111A (en) 1994-02-05 1997-10-21 Baxter International Inc. Dual sensor air-in-line detector
US5460619A (en) 1994-04-04 1995-10-24 Esrock; Bernard S. Disposable tubular device and method
US5441231A (en) 1994-05-17 1995-08-15 Payne; Barrett M. M. Valve closing actuator
DE4421126A1 (en) 1994-06-16 1995-12-21 Fresenius Ag peritoneal dialysis
US5632894A (en) 1994-06-24 1997-05-27 Gish Biomedical, Inc. Arterial blood filter with upwardly inclining delivery inlet conduit
US5541344A (en) 1994-06-30 1996-07-30 G. D. Searle & Co. Intermediates useful in a process for the preparation of azanoradamantane benzamides
FR2723002B1 (en) * 1994-07-26 1996-09-06 Hospal Ind Device and process for preparing a filtration treatment liquid
FR2725522B1 (en) 1994-10-07 1997-01-03 Hospal Ind Device for detecting a conduit and for determining at least one characteristic of its content
US5581687A (en) 1994-11-10 1996-12-03 Baxter International Inc. Interactive control systems for medical processing devices
US5593290A (en) * 1994-12-22 1997-01-14 Eastman Kodak Company Micro dispensing positive displacement pump
US5601080A (en) * 1994-12-28 1997-02-11 Coretech Medical Technologies Corporation Spectrophotometric blood analysis
US5755275A (en) 1995-01-25 1998-05-26 Delta Temax Inc. Tubed lamination heat transfer articles and method of manufacture
US6153102A (en) 1995-02-13 2000-11-28 Aksys, Ltd. Disinfection of dead-ended lines in medical instruments
US5788851A (en) 1995-02-13 1998-08-04 Aksys, Ltd. User interface and method for control of medical instruments, such as dialysis machines
US5591344A (en) 1995-02-13 1997-01-07 Aksys, Ltd. Hot water disinfection of dialysis machines, including the extracorporeal circuit thereof
US5932103A (en) 1995-02-13 1999-08-03 Aksys, Ltd. Withdrawal of priming fluid from extracorporeal circuit of hemodialysis machines or the like
US5932110A (en) 1995-02-13 1999-08-03 Aksys, Ltd. Dialysate conductivity adjustment in a batch dialysate preparation system
US6044868A (en) 1995-02-24 2000-04-04 Arlington Industries, Inc. Watertight fitting for flexible non-metallic conduit
US5586438A (en) 1995-03-27 1996-12-24 Organ, Inc. Portable device for preserving organs by static storage or perfusion
US5578012A (en) 1995-04-24 1996-11-26 Deka Products Limited Partnership Medical fluid pump
US5651765A (en) 1995-04-27 1997-07-29 Avecor Cardiovascular Inc. Blood filter with concentric pleats and method of use
US5839715A (en) 1995-05-16 1998-11-24 Alaris Medical Systems, Inc. Medical adapter having needleless valve and sharpened cannula
ES2094700B1 (en) 1995-05-30 1997-08-01 Serv Reg Salud Com Madrid Device for pumping blood tubular with active valves governed by vacuum and application thereof.
US6139819A (en) 1995-06-07 2000-10-31 Imarx Pharmaceutical Corp. Targeted contrast agents for diagnostic and therapeutic use
US5729653A (en) * 1995-06-07 1998-03-17 Urosurge, Inc. Fluid warming system
US5755683A (en) 1995-06-07 1998-05-26 Deka Products Limited Partnership Stopcock valve
US6709417B1 (en) 1995-06-07 2004-03-23 Deka Products Limited Partnership Valve for intravenous-line flow-control system
US5650071A (en) 1995-06-07 1997-07-22 Cobe Laboratories, Inc. Technique for priming and recirculating fluid through a dialysis machine to prepare the machine for use
US5772624A (en) 1995-07-20 1998-06-30 Medisystems Technology Corporation Reusable blood lines
US5730720A (en) 1995-08-18 1998-03-24 Ip Scientific, Inc. Perfusion hyperthermia treatment system and method
US5674190A (en) 1995-08-28 1997-10-07 Organetics, Ltd. Extracorporeal whole body hyperthermia using alpha-stat regulation of blood pH and pCO2
US5938634A (en) 1995-09-08 1999-08-17 Baxter International Inc. Peritoneal dialysis system with variable pressure drive
US5674109A (en) 1995-09-13 1997-10-07 Ebara Corporation Apparatus and method for polishing workpiece
WO1997009898A1 (en) 1995-09-13 1997-03-20 Philips Electronics N.V. Hair-care appliance with hair-moistness measurement by measuring the resistance of the hair, and circuit for converting the resistance value of a resistor into a measurement signal
US6331778B1 (en) 1995-09-27 2001-12-18 Leak Location Services, Inc. Methods for detecting and locating leaks in containment facilities using electrical potential data and electrical resistance tomographic imaging techniques
JPH0999060A (en) 1995-10-04 1997-04-15 Terumo Corp Pulsatile blood pump
US5692729A (en) 1996-02-16 1997-12-02 Vision-Sciences, Inc. Pressure equalized flow control apparatus and method for endoscope channels
GB9607471D0 (en) * 1996-04-10 1996-06-12 Baxter Int Volumetric infusion pump
US6146354A (en) 1996-05-24 2000-11-14 Horizon Medical Products Asymmetrical multi-lumen apheresis catheter with balanced flow rates
US6783328B2 (en) 1996-09-30 2004-08-31 Terumo Cardiovascular Systems Corporation Method and apparatus for controlling fluid pumps
US6047108A (en) 1996-10-01 2000-04-04 Baxter International Inc. Blood warming apparatus
US5875282A (en) 1996-10-21 1999-02-23 Gaymar Industries, Inc. Medical apparatus for warming patient fluids
US5734464A (en) * 1996-11-06 1998-03-31 Cobe Laboratories, Inc. Red blood cell spillover detection technique
WO1998019529A1 (en) 1996-11-07 1998-05-14 21St Century Medicine, Inc. A method for rapid cooling and warming of biological materials
EP0952858B1 (en) 1996-11-22 2005-01-12 Therakos, Inc. Integrated cassette for valving, pumping and controlling movement of fluids
US5882047A (en) * 1996-12-20 1999-03-16 Itt Automotive, Inc. Quick connector fluid coupling
US6579253B1 (en) 1997-02-14 2003-06-17 Nxstage Medical, Inc. Fluid processing systems and methods using extracorporeal fluid flow panels oriented within a cartridge
US7147613B2 (en) 1997-02-14 2006-12-12 Nxstage Medical, Inc. Measurement of fluid pressure in a blood treatment device
US6852090B2 (en) 1997-02-14 2005-02-08 Nxstage Medical, Inc. Fluid processing systems and methods using extracorporeal fluid flow panels oriented within a cartridge
US6638478B1 (en) 1997-02-14 2003-10-28 Nxstage Medical, Inc. Synchronized volumetric fluid balancing systems and methods
US6673314B1 (en) * 1997-02-14 2004-01-06 Nxstage Medical, Inc. Interactive systems and methods for supporting hemofiltration therapies
WO1998037801A1 (en) 1997-02-27 1998-09-03 Minnesota Mining And Manufacturing Company Cassette for measuring parameters of blood
DE19708391C1 (en) * 1997-03-01 1998-10-22 Fresenius Medical Care De Gmbh Method and apparatus for ultrafiltration during hemodialysis
US5899873A (en) 1997-03-24 1999-05-04 Quest Medical, Inc. Biological fluid delivery system
US6660974B2 (en) 1997-04-07 2003-12-09 Medical Solutions, Inc. Warming system and method for heating various items utilized in surgical procedures
US5804979A (en) 1997-05-13 1998-09-08 Fluke Corporation Circuit for measuring in-circuit resistance and current
US6070761A (en) 1997-08-22 2000-06-06 Deka Products Limited Partnership Vial loading method and apparatus for intelligent admixture and delivery of intravenous drugs
EP1003579B1 (en) 1997-08-22 2005-01-12 Deka Products Limited Partnership System and cassette for mixing and delivering intravenous drugs
DE19739099C1 (en) * 1997-09-06 1999-01-28 Fresenius Medical Care De Gmbh Monitoring of a blood container inlet during external blood treatment
US5925831A (en) 1997-10-18 1999-07-20 Cardiopulmonary Technologies, Inc. Respiratory air flow sensor
US6159192A (en) 1997-12-04 2000-12-12 Fowles; Thomas A. Sliding reconstitution device with seal
CH692570A5 (en) * 1997-12-05 2002-08-15 Peter F Meier Apparatus for monitoring a catheter device.
US6109881A (en) 1998-01-09 2000-08-29 Snodgrass; Ocie T. Gas driven pump for the dispensing and filtering of process fluid
DE69922354T2 (en) 1998-01-23 2005-11-24 Viacirq, Inc. Apparatus and method for whole body hyperthermia treatment
JPH11210633A (en) 1998-01-30 1999-08-03 Matsushita Electric Works Ltd Suction device
US6142164A (en) 1998-03-09 2000-11-07 Ultra Clean Technology Systems & Service, Inc. Method and apparatus for removing leaking gas in an integrated gas panel system
DE19814695C2 (en) 1998-04-01 2001-09-13 Fresenius Medical Care De Gmbh Cassette for conveying liquids, in particular dialysis fluids, dialysis apparatus and method for conveying, accounted for, and dispensing of medical fluid heating
US6343614B1 (en) * 1998-07-01 2002-02-05 Deka Products Limited Partnership System for measuring change in fluid flow rate within a line
US6041801A (en) 1998-07-01 2000-03-28 Deka Products Limited Partnership System and method for measuring when fluid has stopped flowing within a line
US6175688B1 (en) 1998-07-10 2001-01-16 Belmont Instrument Corporation Wearable intravenous fluid heater
SE513522C2 (en) 1998-09-10 2000-09-25 Gambro Ab Device for monitoring a fluid pipe
JP2000107283A (en) 1998-10-07 2000-04-18 Nissho Corp Dialysis apparatus and washing priming method
AU769442B2 (en) 1998-10-16 2004-01-29 Terumo Medical Corporation Blood processing system
US6223130B1 (en) 1998-11-16 2001-04-24 Deka Products Limited Partnership Apparatus and method for detection of a leak in a membrane of a fluid flow control system
SE9804142D0 (en) * 1998-11-30 1998-11-30 Gambro Ab Method and Device for Providing a signal
CN2374187Y (en) 1999-01-29 2000-04-19 暨南大学 Blood dialyser
DE60000728T2 (en) 1999-03-09 2003-08-21 Augustine Medical Inc A means for heating IV fluid with detecting the presence and alignment of a cassette
US6579496B1 (en) 1999-05-25 2003-06-17 Viacirq, Inc. Apparatus for implementing hyperthermia
US6321597B1 (en) 1999-05-28 2001-11-27 Deka Products Limited Partnership System and method for measuring volume of liquid in a chamber
US7168334B1 (en) * 2000-05-30 2007-01-30 Gambro Lundia Ab Arrangement for measuring a property of a fluid present in a tube
DE19925297C1 (en) 1999-06-02 2000-07-13 Braun Melsungen Ag Dialysis machine filter cartridge holder uses radial tensioner elements to seal onto cartridge connections when positioned using keyhole holder connections taking cartridge connection grooves.
US6336911B1 (en) * 1999-06-16 2002-01-08 First Circle Medical, Inc. Thermal sensor for hyperthermia system
US6406452B1 (en) 1999-06-16 2002-06-18 First Circle Medical, Inc. Bladder catheter for hyperthermia system
DE19928407C1 (en) 1999-06-22 2000-10-26 Fresenius Medical Care De Gmbh Determining dialyser performance in dialysis device involves determining clearance and dialysance based on values for given blood/dialysis liquid flow rates and/or ultrafiltration rate
US6176904B1 (en) * 1999-07-02 2001-01-23 Brij M. Gupta Blood filter
US6604908B1 (en) 1999-07-20 2003-08-12 Deka Products Limited Partnership Methods and systems for pulsed delivery of fluids from a pump
US6877713B1 (en) 1999-07-20 2005-04-12 Deka Products Limited Partnership Tube occluder and method for occluding collapsible tubes
US6416293B1 (en) 1999-07-20 2002-07-09 Deka Products Limited Partnership Pumping cartridge including a bypass valve and method for directing flow in a pumping cartridge
US6382923B1 (en) 1999-07-20 2002-05-07 Deka Products Ltd. Partnership Pump chamber having at least one spacer for inhibiting the pumping of a gas
US6905479B1 (en) 1999-07-20 2005-06-14 Deka Products Limited Partnership Pumping cartridge having an integrated filter and method for filtering a fluid with the cartridge
US6302653B1 (en) 1999-07-20 2001-10-16 Deka Products Limited Partnership Methods and systems for detecting the presence of a gas in a pump and preventing a gas from being pumped from a pump
US6171261B1 (en) * 1999-08-06 2001-01-09 Becton Dickinson And Company Specimen collection device and method of delivering fluid specimens to test tubes
US6949079B1 (en) 1999-09-03 2005-09-27 Baxter International Inc. Programmable, fluid pressure actuated blood processing systems and methods
US20060178612A9 (en) 1999-09-03 2006-08-10 Baxter International Inc. Blood processing systems with fluid flow cassette with a pressure actuated pump chamber and in-line air trap
US7041076B1 (en) 1999-09-03 2006-05-09 Baxter International Inc. Blood separation systems and methods using a multiple function pump station to perform different on-line processing tasks
US6284142B1 (en) 1999-09-03 2001-09-04 Baxter International Inc. Sensing systems and methods for differentiating between different cellular blood species during extracorporeal blood separation or processing
US6723062B1 (en) 1999-09-03 2004-04-20 Baxter International Inc. Fluid pressure actuated blood pumping systems and methods with continuous inflow and pulsatile outflow conditions
US6448845B2 (en) * 1999-09-30 2002-09-10 Koninklijke Philips Electronics N.V. Trimmable reference generator
US6464666B1 (en) 1999-10-08 2002-10-15 Augustine Medical, Inc. Intravenous fluid warming cassette with stiffening member and integral handle
US6687004B1 (en) * 1999-10-22 2004-02-03 Marquette University Optical sensor for opaque and non-opaque materials
US6406426B1 (en) 1999-11-03 2002-06-18 Criticare Systems Medical monitoring and alert system for use with therapeutic devices
IT1308687B1 (en) * 1999-12-28 2002-01-09 Gambro Dasco Spa Method and device for detecting access to sistemacardivascolare in an extracorporeal blood treatment in a
US6423053B1 (en) 2000-01-12 2002-07-23 Han-Pin Lee Releasable tube assembly
US6347633B1 (en) * 2000-01-14 2002-02-19 First Circle Medical, Inc. Treatment of hepatitis C using hyperthermia
US6139534A (en) * 2000-01-24 2000-10-31 Bracco Diagnostics, Inc. Vial access adapter
US6497676B1 (en) 2000-02-10 2002-12-24 Baxter International Method and apparatus for monitoring and controlling peritoneal dialysis therapy
WO2001065214A2 (en) 2000-02-29 2001-09-07 Gen-Probe Incorporated Fluid dispense and liquid surface verification system and method
US6595944B2 (en) 2000-06-17 2003-07-22 Fresenius Medical Care Deutschland Gmbh Dialysis machine and method of operating a dialysis machine
US6517510B1 (en) * 2000-06-26 2003-02-11 Gaymar Industries, Inc. Automatic patient control device
US6415797B1 (en) 2000-07-07 2002-07-09 First Circle Medical, Inc. Treatment of human herpesviruses using hyperthermia
AU6525301A (en) 2000-07-07 2002-01-21 First Circle Medical Inc Treatment of hiv using hyperthermia
US6503062B1 (en) 2000-07-10 2003-01-07 Deka Products Limited Partnership Method for regulating fluid pump pressure
US6635491B1 (en) 2000-07-28 2003-10-21 Abbott Labortories Method for non-invasively determining the concentration of an analyte by compensating for the effect of tissue hydration
US6543814B2 (en) 2000-08-10 2003-04-08 John M. Bartholomew Quick connector
US6788885B2 (en) 2000-09-01 2004-09-07 Michael Mitsunaga System for heating instillation or transfusion liquids
US6336003B1 (en) * 2000-09-01 2002-01-01 Automatic Medical Technologies, Inc. Max one I.V. warmer
WO2002023167A1 (en) * 2000-09-11 2002-03-21 The Government Of The United States Of America, As Represented By The Secretary Of The Navy Fluidics system
IT1320264B1 (en) 2000-09-29 2003-11-26 Gambro Dasco Spa Apparatus dialysis and method for verifying the functionality 'ofa dialysis equipment.
US6785934B2 (en) 2000-10-02 2004-09-07 Cornice Technologies Inc Universal vacuum extension kit
EP1195171B1 (en) 2000-10-04 2012-08-15 Terumo Kabushiki Kaisha Peritoneal dialysis apparatus
MXPA03003105A (en) 2000-10-12 2004-01-26 Renal Solutions Inc Devices and methods for body fluid flow control in extracorporeal fluid treatments.
DE10053441B4 (en) 2000-10-27 2004-04-15 Fresenius Medical Care Deutschland Gmbh Disposable cartridge with sealing membrane and valve actuator for this purpose
US6689083B1 (en) * 2000-11-27 2004-02-10 Chf Solutions, Inc. Controller for ultrafiltration blood circuit which prevents hypotension by monitoring osmotic pressure in blood
US6814718B2 (en) 2001-01-09 2004-11-09 Rex Medical, L.P Dialysis catheter
US6529775B2 (en) * 2001-01-16 2003-03-04 Alsius Corporation System and method employing indwelling RF catheter for systemic patient warming by application of dielectric heating
US6539172B2 (en) 2001-01-31 2003-03-25 Kabushiki Kaisha Sanko Fluid heating device and cartridge for the same
EP1399193B1 (en) 2001-02-16 2014-01-08 Piedmont Renal Clinics, P.A. Automated peritoneal dialysis system and process with in-line sterilization of dialysate
WO2002094359A1 (en) 2001-05-23 2002-11-28 Metran Co., Ltd. Inspired air temperature measuring device in respiratory circuit
DE10126134B4 (en) 2001-05-29 2004-02-26 W.E.T. Automotive Systems Ag Large-area heating element
US6527758B2 (en) * 2001-06-11 2003-03-04 Kam Ko Vial docking station for sliding reconstitution with diluent container
ITTO20010582A1 (en) 2001-06-15 2002-12-16 Gambro Dasco Spa A method and device of venous needle of detachment detection by a patient during an extracorporeal blood treatment in a mach
US7641864B2 (en) 2001-06-15 2010-01-05 Avure Technologies Incorporated Thermal sensor connector for pressure vessel
US6768085B2 (en) 2001-07-02 2004-07-27 Medical Solutions, Inc. Medical solution warming system and method of heating and maintaining medical solutions at desired temperatures
US6649063B2 (en) 2001-07-12 2003-11-18 Nxstage Medical, Inc. Method for performing renal replacement therapy including producing sterile replacement fluid in a renal replacement therapy unit
US6722865B2 (en) 2001-09-07 2004-04-20 Terumorcardiovascular Systems Corporation Universal tube clamp assembly
US6868309B1 (en) 2001-09-24 2005-03-15 Aksys, Ltd. Dialysis machine with symmetric multi-processing (SMP) control system and method of operation
US6905314B2 (en) 2001-10-16 2005-06-14 Baxter International Inc. Pump having flexible liner and compounding apparatus having such a pump
US7241272B2 (en) 2001-11-13 2007-07-10 Baxter International Inc. Method and composition for removing uremic toxins in dialysis processes
US7854718B2 (en) 2001-11-16 2010-12-21 Fresenius Medical Care Holdings, Inc. Dual-ventricle pump cartridge, pump and method of use in a wearable continuous renal replacement therapy device
US7645253B2 (en) 2001-11-16 2010-01-12 National Quality Care, Inc. Wearable ultrafiltration device
US6608968B2 (en) 2001-11-23 2003-08-19 Allan P Bakke Convection blood warming system with disposable flattened tube envelope incorporating paperboard “needle” for inserting envelope between heating plates and employing active and passive insulation of outlet flow path to provide normothermic fluid at zero to 600 milliliters per minute
US8226605B2 (en) 2001-12-17 2012-07-24 Medical Solutions, Inc. Method and apparatus for heating solutions within intravenous lines to desired temperatures during infusion
ITMI20012829A1 (en) * 2001-12-28 2003-06-30 Gambro Dasco Spa An apparatus and control method in an extracorporeal circuit disangue
US7122210B2 (en) 2002-01-11 2006-10-17 Baxter International Inc. Bicarbonate-based solutions for dialysis therapies
SE0200760L (en) 2002-03-14 2003-06-24 Billy Nilson Ambulatory diaphragm pump
DE10212247C1 (en) 2002-03-19 2003-12-18 Fresenius Medical Care De Gmbh A method for determining a treatment parameter at a hemofiltration and hemofiltration apparatus for applying the method
AUPS140902A0 (en) 2002-03-27 2002-05-09 Lazer Safe Pty Ltd Multiple laser safety system
US7052480B2 (en) * 2002-04-10 2006-05-30 Baxter International Inc. Access disconnection systems and methods
US7138088B2 (en) * 2002-04-10 2006-11-21 Baxter International Inc. Access disconnection system and methods
US10155082B2 (en) 2002-04-10 2018-12-18 Baxter International Inc. Enhanced signal detection for access disconnection systems
AU2003230862A1 (en) 2002-04-11 2003-10-27 Deka Products Limited Partnership System and method for delivering a target volume of fluid
DE10216146A1 (en) 2002-04-12 2003-10-30 Bayer Ag diaphragm pump
US6946299B2 (en) * 2002-04-25 2005-09-20 Home Diagnostics, Inc. Systems and methods for blood glucose sensing
CN1455262A (en) * 2002-05-04 2003-11-12 朱筱杰 Resistance measuring circuit and detection, control and alarm apparatus comprising said circuit
US6947131B2 (en) 2002-05-07 2005-09-20 Chf Solutions, Inc. Blood leak detector for extracorporeal treatment system
ITMI20021028A1 (en) * 2002-05-14 2003-11-14 Dideco Spa Unita 'pumping fluid in particular blood
US20030220607A1 (en) 2002-05-24 2003-11-27 Don Busby Peritoneal dialysis apparatus
US6939111B2 (en) 2002-05-24 2005-09-06 Baxter International Inc. Method and apparatus for controlling medical fluid pressure
US7175606B2 (en) * 2002-05-24 2007-02-13 Baxter International Inc. Disposable medical fluid unit having rigid frame
US7153286B2 (en) 2002-05-24 2006-12-26 Baxter International Inc. Automated dialysis system
US6929751B2 (en) 2002-05-24 2005-08-16 Baxter International Inc. Vented medical fluid tip protector methods
US7115228B2 (en) 2002-05-24 2006-10-03 Baxter International Inc. One-piece tip protector and organizer
DE10224750A1 (en) 2002-06-04 2003-12-24 Fresenius Medical Care De Gmbh An apparatus for treating a medical fluid
US20040009096A1 (en) * 2002-06-08 2004-01-15 Wellman Parris S. Substantially inertia free hemodialysis
DE10227193B4 (en) 2002-06-18 2007-05-10 Ulman Dichtungstechnik Gmbh Composite membrane for diaphragm pumps
JP4890761B2 (en) * 2002-07-19 2012-03-07 バクスター・インターナショナル・インコーポレイテッドBaxter International Incorp0Rated System and method for performing peritoneal dialysis
US7238164B2 (en) * 2002-07-19 2007-07-03 Baxter International Inc. Systems, methods and apparatuses for pumping cassette-based therapies
EP1394366B1 (en) 2002-09-02 2007-03-07 BorgWarner Inc. Turbomachine housing
US7175397B2 (en) * 2002-09-27 2007-02-13 Pulsafeeder, Inc. Effervescent gas bleeder apparatus
US20040138607A1 (en) 2002-10-08 2004-07-15 Burbank Jeffrey H. Cartridge-based medical fluid processing system
WO2004041081A1 (en) 2002-11-01 2004-05-21 Nxstage Medical, Inc. Functional isolation of upgradeable components to reduce risk in medical treatment devices
DE10256923B4 (en) * 2002-12-05 2013-10-24 Liebherr-France S.A. Method and apparatus for damping the movement of hydraulic cylinders of mobile working machines
US7247146B2 (en) 2003-02-07 2007-07-24 Gambro Lundia Ab Support element for an integrated blood treatment module, integrated blood treatment module and extracorporeal blood treatment apparatus equipped with said integrated module
WO2004105589A2 (en) * 2003-05-28 2004-12-09 Hemocleanse Technologies, Llc Sorbent reactor for extracorporeal blood treatment systems, peritoneal dialysis systems, and other body fluid treatment systems
JP4286073B2 (en) 2003-06-18 2009-06-24 ニプロ株式会社 Dialyzer connecting coupler
JP4041018B2 (en) 2003-06-25 2008-01-30 Tdk株式会社 Temperature sensor
US20050049539A1 (en) 2003-09-03 2005-03-03 O'hara Gerald P. Control system for driving fluids through an extracorporeal blood circuit
JP4732726B2 (en) 2003-09-09 2011-07-27 セイコーインスツル株式会社 A method of manufacturing a semiconductor device
US6826948B1 (en) 2003-10-09 2004-12-07 Delphi Technologies, Inc. Leak detection apparatus for a liquid circulation cooling system
SE0302698L (en) 2003-10-13 2005-04-14 Gambro Lundia Ab Apparatus for implementing a peritoneal dialysis treatment
US7029456B2 (en) 2003-10-15 2006-04-18 Baxter International Inc. Medical fluid therapy flow balancing and synchronization system
MX351817B (en) 2003-10-28 2017-10-30 Baxter Healthcare Sa Improved priming, integrity and head height methods and apparatuses for medical fluid systems.
US20050095141A1 (en) 2003-10-30 2005-05-05 Deka Products Limited Partnership System and method for pumping fluid using a pump cassette
US8038639B2 (en) 2004-11-04 2011-10-18 Baxter International Inc. Medical fluid system with flexible sheeting disposable unit
US8029454B2 (en) 2003-11-05 2011-10-04 Baxter International Inc. High convection home hemodialysis/hemofiltration and sorbent system
US7776006B2 (en) * 2003-11-05 2010-08-17 Baxter International Inc. Medical fluid pumping system having real time volume determination
CN1890031B (en) 2003-12-04 2010-09-29 皇家飞利浦电子股份有限公司 Ultrasound transducer and method for implementing flip-chip two dimensional array technology to curved arrays
US7744553B2 (en) 2003-12-16 2010-06-29 Baxter International Inc. Medical fluid therapy flow control systems and methods
US7488448B2 (en) * 2004-03-01 2009-02-10 Indian Wells Medical, Inc. Method and apparatus for removal of gas bubbles from blood
US20050195087A1 (en) 2004-03-04 2005-09-08 Thompson Holly R. Air-in-line detector with warning device
US7899508B2 (en) * 2004-03-11 2011-03-01 Board Of Regents, The University Of Texas System Intracorporeal impedance and leak monitoring device
US20050209563A1 (en) 2004-03-19 2005-09-22 Peter Hopping Cassette-based dialysis medical fluid therapy systems, apparatuses and methods
US7303540B2 (en) 2004-04-26 2007-12-04 Chf Solutions, Inc. User interface for blood treatment device
US20070210047A1 (en) 2004-05-10 2007-09-13 Child Kent R System and method for automatically clamping a tube in an orbital welder
US7776210B2 (en) 2004-06-09 2010-08-17 Renal Solutions, Inc. Dialysis system
US7124996B2 (en) 2004-07-16 2006-10-24 Cardinal Health 303, Inc. Automatic clamp apparatus for IV infusion sets used in pump devices
GB0417337D0 (en) 2004-08-04 2004-09-08 Chu Andrew C Low cost air bubble detector and alarm system for fluid administrative applications
US7476209B2 (en) 2004-12-21 2009-01-13 Therakos, Inc. Method and apparatus for collecting a blood component and performing a photopheresis treatment
JP2006204343A (en) 2005-01-25 2006-08-10 Hiroshima Univ Auxiliary artificial heart
GB2423241A (en) 2005-01-25 2006-08-23 Spaceace Ltd Object sensing device associated with moving furniture
US20060189926A1 (en) * 2005-02-14 2006-08-24 Hall W D Apparatus and methods for analyzing body fluid samples
SE532147C2 (en) 2005-02-16 2009-11-03 Triomed Ab Portable dialysis systems
US20060195064A1 (en) 2005-02-28 2006-08-31 Fresenius Medical Care Holdings, Inc. Portable apparatus for peritoneal dialysis therapy
US7935074B2 (en) 2005-02-28 2011-05-03 Fresenius Medical Care Holdings, Inc. Cassette system for peritoneal dialysis machine
RU2007138432A (en) 2005-03-17 2009-04-27 НОКС II ИНТЕНЭШНЛ, эЛТиДи. (US) Coal combustion method (embodiments), the installation for the combustion of coal and a method for reducing the amount of sulfur and mercury emitted during combustion of coal (variants)
US8734404B2 (en) * 2005-03-17 2014-05-27 Patented Medical Solutions, Llc Lay flat tubing
WO2006120417A2 (en) 2005-05-06 2006-11-16 Imi Vision Limited Fluid processing apparatus
DE102005024363B4 (en) * 2005-05-27 2012-09-20 Fresenius Medical Care Deutschland Gmbh Apparatus and method for conveying liquids
US7530962B2 (en) 2005-06-16 2009-05-12 Edward Allan Ross Method for detecting the disconnection of an extracorporeal device using a patient's endogenous electrical voltages
US7717682B2 (en) 2005-07-13 2010-05-18 Purity Solutions Llc Double diaphragm pump and related methods
US8197231B2 (en) 2005-07-13 2012-06-12 Purity Solutions Llc Diaphragm pump and related methods
JP4798653B2 (en) * 2005-11-18 2011-10-19 日機装株式会社 Blood purification apparatus
US7857506B2 (en) 2005-12-05 2010-12-28 Sencal Llc Disposable, pre-calibrated, pre-validated sensors for use in bio-processing applications
US20070179436A1 (en) 2005-12-21 2007-08-02 Braig James R Analyte detection system with periodic sample draw and laboratory-grade analyzer
DE602007008395D1 (en) 2006-04-07 2010-09-23 Nxstage Medical Inc Hose clamp for medical applications
CN100460026C (en) 2006-04-12 2009-02-11 重庆山外山科技有限公司 Medical hemodialysis filter
MX2008013266A (en) 2006-04-14 2008-10-27 Deka Products Lp Systems, devices and methods for fluid pumping, heat exchange, thermal sensing, and conductivity sensing.
US20170326282A1 (en) 2006-04-14 2017-11-16 Deka Products Limited Partnership Blood treatment systems and methods
US8366316B2 (en) 2006-04-14 2013-02-05 Deka Products Limited Partnership Sensor apparatus systems, devices and methods
EP2012848A4 (en) 2006-04-27 2013-12-25 Gambro Lundia Ab Remote controlled medical apparatus
ITRM20060232A1 (en) 2006-04-28 2007-10-29 Blue Magic S R L A dispensing device for hydraulic systems
US20080287854A1 (en) 2006-06-24 2008-11-20 Jiandong Sun Emergency-Disengagement Device for Patients Undergoing Hemodialysis
WO2008010004A1 (en) 2006-07-14 2008-01-24 Gambro Lundia Ab Blood processing apparatus
US7644889B2 (en) * 2006-07-18 2010-01-12 Insitu, Inc. Fluid sensing system and methods, including vehicle fuel sensors
US8926550B2 (en) 2006-08-31 2015-01-06 Fresenius Medical Care Holdings, Inc. Data communication system for peritoneal dialysis machine
US20080058712A1 (en) 2006-08-31 2008-03-06 Plahey Kulwinder S Peritoneal dialysis machine with dual voltage heater circuit and method of operation
US8870811B2 (en) 2006-08-31 2014-10-28 Fresenius Medical Care Holdings, Inc. Peritoneal dialysis systems and related methods
DE102006042336A1 (en) * 2006-09-08 2008-03-27 Fresenius Medical Care Deutschland Gmbh Apparatus and method for monitoring an access to a patient, in particular a vascular access in extracorporeal blood treatment
DE102006042646B4 (en) 2006-09-12 2008-11-20 Fresenius Medical Care Deutschland Gmbh Apparatus and method for monitoring an access to a patient, in particular a vascular access in extracorporeal blood treatment
FR2907259A1 (en) 2006-10-13 2008-04-18 St Microelectronics Sa Realization of a metal gate in an electronic circuit integrated
WO2008065950A1 (en) 2006-12-01 2008-06-05 Jms Co., Ltd. State detecting device
JP5141004B2 (en) 2006-12-01 2013-02-13 株式会社ジェイ・エム・エス State detecting device
CN101206517B (en) 2006-12-22 2011-06-22 奇美电子股份有限公司 Computer
US20080161751A1 (en) 2006-12-29 2008-07-03 Plahey Kulwinder S Peritoneal dialysis therapy validation
US8226293B2 (en) 2007-02-22 2012-07-24 Medical Solutions, Inc. Method and apparatus for measurement and control of temperature for infused liquids
WO2009051669A1 (en) 2007-10-12 2009-04-23 Deka Products Limited Partnership Apparatus and methods for hemodialysis
WO2008106452A1 (en) 2007-02-27 2008-09-04 Deka Products Limited Partnership Peritoneal dialysis sensor apparatus systems, devices and methods
US8425471B2 (en) 2007-02-27 2013-04-23 Deka Products Limited Partnership Reagent supply for a hemodialysis system
US8562834B2 (en) 2007-02-27 2013-10-22 Deka Products Limited Partnership Modular assembly for a portable hemodialysis system
US7967022B2 (en) 2007-02-27 2011-06-28 Deka Products Limited Partnership Cassette system integrated apparatus
US20160058933A1 (en) 2007-02-27 2016-03-03 Deka Products Limited Partnership Control Systems and Methods for Blood or Fluid Handling Medical Devices
US8357298B2 (en) * 2007-02-27 2013-01-22 Deka Products Limited Partnership Hemodialysis systems and methods
KR101385448B1 (en) 2007-02-27 2014-04-15 삼성디스플레이 주식회사 Circuit for driving source wire and display device having the same
US20090107335A1 (en) 2007-02-27 2009-04-30 Deka Products Limited Partnership Air trap for a medical infusion device
US8042563B2 (en) 2007-02-27 2011-10-25 Deka Products Limited Partnership Cassette system integrated apparatus
US8409441B2 (en) 2007-02-27 2013-04-02 Deka Products Limited Partnership Blood treatment systems and methods
US8491184B2 (en) 2007-02-27 2013-07-23 Deka Products Limited Partnership Sensor apparatus systems, devices and methods
US20140199193A1 (en) 2007-02-27 2014-07-17 Deka Products Limited Partnership Blood treatment systems and methods
MX349329B (en) 2008-08-27 2017-07-21 Deka Products Lp Control architecture and methods for blood treatment systems.
US9028691B2 (en) 2007-02-27 2015-05-12 Deka Products Limited Partnership Blood circuit assembly for a hemodialysis system
KR101505213B1 (en) * 2007-02-27 2015-03-30 데카 프로덕츠 리미티드 파트너쉽 Hemodialysis System and Methods
WO2008118400A1 (en) 2007-03-22 2008-10-02 Nanologix, Inc. Detection and identification of microorganisms on transparent permeable membranes
US20080240929A1 (en) 2007-03-30 2008-10-02 Deka Products Limited Partnership Pumping Cassette
WO2008129084A1 (en) 2007-04-23 2008-10-30 Fundación Para La Investigación Biomédica Del Hospital Gregorio Marañon Haemodialfiltration method and apparatus
EP2002855B1 (en) 2007-06-14 2012-07-11 RenApta B.V. Artificial kidney
US8715235B2 (en) * 2007-07-05 2014-05-06 Baxter International Inc. Dialysis system having disposable cassette and heated cassette interface
US8057423B2 (en) * 2007-07-05 2011-11-15 Baxter International Inc. Dialysis system having disposable cassette
US7955295B2 (en) * 2007-07-05 2011-06-07 Baxter International Inc. Fluid delivery system with autoconnect features
US7736328B2 (en) * 2007-07-05 2010-06-15 Baxter International Inc. Dialysis system having supply container autoconnection
US8330579B2 (en) * 2007-07-05 2012-12-11 Baxter International Inc. Radio-frequency auto-identification system for dialysis systems
US8287724B2 (en) * 2007-07-05 2012-10-16 Baxter International Inc. Dialysis fluid measurement systems using conductive contacts
US8105266B2 (en) * 2007-07-05 2012-01-31 Baxter International Inc. Mobile dialysis system having supply container detection
US7901376B2 (en) * 2007-07-05 2011-03-08 Baxter International Inc. Dialysis cassette having multiple outlet valve
US8764702B2 (en) * 2007-07-05 2014-07-01 Baxter International Inc. Dialysis system having dual patient line connection and prime
US7905855B2 (en) * 2007-07-05 2011-03-15 Baxter International Inc. Dialysis system having non-invasive temperature sensing
US7909795B2 (en) * 2007-07-05 2011-03-22 Baxter International Inc. Dialysis system having disposable cassette and interface therefore
US7790103B2 (en) * 2007-07-05 2010-09-07 Baxter International Inc. Extended use dialysis system
US7957927B2 (en) * 2007-07-05 2011-06-07 Baxter International Inc. Temperature compensation for pneumatic pumping system
US20090007642A1 (en) * 2007-07-05 2009-01-08 Baxter International Inc. Dialysis fluid measurement method and apparatus using conductive contacts
US8496609B2 (en) * 2007-07-05 2013-07-30 Baxter International Inc. Fluid delivery system with spiked cassette
US20090076434A1 (en) 2007-09-13 2009-03-19 Mischelevich David J Method and System for Achieving Volumetric Accuracy in Hemodialysis Systems
CN102784422B (en) 2007-09-19 2015-05-06 弗雷塞尼斯医疗保健控股公司 Dialysis systems and related components
US7892197B2 (en) * 2007-09-19 2011-02-22 Fresenius Medical Care Holdings, Inc. Automatic prime of an extracorporeal blood circuit
US8444587B2 (en) 2007-10-01 2013-05-21 Baxter International Inc. Fluid and air handling in blood and dialysis circuits
US7887495B2 (en) 2007-10-18 2011-02-15 Boyd Lawrence M Protective and cosmetic covering for external fixators
US8858787B2 (en) 2007-10-22 2014-10-14 Baxter International Inc. Dialysis system having non-invasive fluid velocity sensing
US8114276B2 (en) 2007-10-24 2012-02-14 Baxter International Inc. Personal hemodialysis system
US7905853B2 (en) 2007-10-30 2011-03-15 Baxter International Inc. Dialysis system having integrated pneumatic manifold
US20090113335A1 (en) 2007-10-30 2009-04-30 Baxter International Inc. Dialysis system user interface
WO2009073567A1 (en) 2007-11-29 2009-06-11 Xcorporeal. Inc. System and method for conducting hemodialysis and hemofiltration
MX340256B (en) 2008-01-23 2016-06-30 Deka Products Lp Fluid line autoconnect apparatus and methods for medical treatment system.
JP4465725B2 (en) * 2008-04-04 2010-05-19 株式会社デンソー Liquid concentration measuring device
EP2113266A1 (en) 2008-04-30 2009-11-04 Gambro Lundia AB Degassing device
US8863772B2 (en) 2008-08-27 2014-10-21 Deka Products Limited Partnership Occluder for a medical infusion system
US8771508B2 (en) 2008-08-27 2014-07-08 Deka Products Limited Partnership Dialyzer cartridge mounting arrangement for a hemodialysis system
AU2009302327C1 (en) 2008-10-07 2015-09-10 Fresenius Medical Care Holdings, Inc. Priming system and method for dialysis systems
AU2010210385A1 (en) 2009-02-06 2011-08-18 Velomedix, Inc. Method and apparatus for inducing therapeutic hypothermia
EP3072545A1 (en) 2009-10-30 2016-09-28 DEKA Products Limited Partnership Apparatus and method for detecting disconnection of an intravascular access device
MX2013000212A (en) 2010-07-07 2013-05-09 Deka Products Lp Medical treatment system and methods using a plurality of fluid lines.
CA2837200A1 (en) 2011-05-24 2012-11-29 Deka Products Limited Partnership Hemodialysis system
EP3263150A1 (en) 2011-05-24 2018-01-03 DEKA Products Limited Partnership Blood treatment systems and methods
US9999717B2 (en) 2011-05-24 2018-06-19 Deka Products Limited Partnership Systems and methods for detecting vascular access disconnection
US9364655B2 (en) 2012-05-24 2016-06-14 Deka Products Limited Partnership Flexible tubing occlusion assembly
US20150196699A9 (en) 2013-03-15 2015-07-16 Deka Products Limited Partnership Blood treatment systems and methods

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4656427A (en) * 1985-02-05 1987-04-07 Dauphinee Thomas M Liquid conductivity measuring circuit
US5469070A (en) * 1992-10-16 1995-11-21 Rosemount Analytical Inc. Circuit for measuring source resistance of a sensor
DE10206666A1 (en) * 2002-02-18 2003-08-28 Siemens Ag Determining measuring resistance of sensor element involves applying measuring voltage over sensor element, varying reference voltage, and comparing measuring voltage with reference voltage
US20090114582A1 (en) 2007-02-27 2009-05-07 Deka Products Limited Partnership Enclosure for a portable hemodialysis system
US20090088683A1 (en) * 2007-10-01 2009-04-02 Baxter International Inc. Adaptive algorithm for access disconnect detection
US20100056975A1 (en) 2008-08-27 2010-03-04 Deka Products Limited Partnership Blood line connector for a medical infusion device

Also Published As

Publication number Publication date
US20110105877A1 (en) 2011-05-05
CN104841030A (en) 2015-08-19
EP2493526B1 (en) 2016-05-04
MX353433B (en) 2018-01-11
JP2015091547A (en) 2015-05-14
EP2493526A2 (en) 2012-09-05
JP2013509271A (en) 2013-03-14
CN104841030B (en) 2017-10-31
WO2011053810A3 (en) 2011-06-30
CA2779296A1 (en) 2011-05-05
WO2011053810A2 (en) 2011-05-05
US10201650B2 (en) 2019-02-12
JP6023237B2 (en) 2016-11-09
MX2012005088A (en) 2012-10-03
JP6321110B2 (en) 2018-05-09
CN102821798A (en) 2012-12-12
CA2779296C (en) 2018-02-13
US20150042366A1 (en) 2015-02-12
JP2017035512A (en) 2017-02-16

Similar Documents

Publication Publication Date Title
US4411648A (en) Iontophoretic catheter device
US3757771A (en) Sterile inserter apparatus
US7347843B2 (en) Vascular access port with needle detector
US7458938B2 (en) Peripherally inserted central catheter with continuous central venous oximetry and proximal high flow port
US6755801B2 (en) Dialysis pressure monitoring with clot suppression
US20020104800A1 (en) Method and apparatus for a hemodiafiltration delivery module
US6254586B1 (en) Method and kit for supplying a fluid to a subcutaneous placement site
DE602004013263T2 (en) Sensor protection device with double membrane
JP2553557B2 (en) Apparatus for monitoring the flow of parenteral fluid
EP2263717B1 (en) Method and device for recognition of stenoses in extra-corporal blood treatment
US7169107B2 (en) Conductivity reconstruction based on inverse finite element measurements in a tissue monitoring system
US5509424A (en) Continuous cardiac output monitoring system
EP0958498B1 (en) Method and apparatus for reducing purge volume in a blood chemistry monitoring system
US20100234786A1 (en) System and Method for Detection of Disconnection in an Extracorporeal Blood Circuit
Hill et al. The effect of haematocrit on the resistivity of human blood at 37 C and 100 kHz
AU2008302742B2 (en) Acoustic access disconnect detection system
US5570026A (en) Altered fluid conductivity monitor
US7276041B2 (en) Method and device for monitoring loss of body fluid and dislodgment of medical instrument from body
US6210591B1 (en) Method to measure blood flow rate in hemodialysis shunts
US5876366A (en) Kidney dialysis method and device
US6912917B2 (en) Differential fluid parameter determination
JP4117505B2 (en) Once-through processing unit
US4791932A (en) Extracorporeal sensing module
WO2001008729A1 (en) Extravasation detection apparatus and method
US6887214B1 (en) Blood pump having a disposable blood passage cartridge with integrated pressure sensors

Legal Events

Date Code Title Description
17P Request for examination filed

Effective date: 20160503

AC Divisional application (art. 76) of:

Ref document number: 2493526

Country of ref document: EP

Kind code of ref document: P

AK Designated contracting states:

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

RIC1 Classification (correction)

Ipc: G01N 27/07 20060101ALI20181116BHEP

Ipc: A61M 1/36 20060101AFI20181116BHEP

INTG Announcement of intention to grant

Effective date: 20181210